CN1684375A - Radio receiver, radio receiving method and recording medium - Google Patents

Abstract

The threshold value of the electric field strength level for starting the AGC operation is set by the signal processor part 107 according to the measurement result of the error rate of the received signal measured by the error rate measurement circuit 109, when the electric field strength detected by the electric field strength detector 105 reaches the electric field for starting the AGC operation When the intensity level threshold is reached, the gain control circuit 106 starts a gain control operation. The electric field strength level threshold for optimally starting AGC operation can be set to suit the radio wave environment in which the radio receiver is located, and the gain control of the gain control device can be obtained to optimize reception in an environment characterized by IM characteristics or electric field strength variations The signal quality of the signal.

Description

radio receiver, radio receiving method

This application is a divisional application of the following patent application: the filing date is September 1, 2000, the application number is 00126449.4, and the title of the invention is "radio receiver, radio receiving method".

technical field

The present invention relates to a radio receiver, a radio receiving method, and a recording medium for recording a program for executing the radio receiving method, and more particularly, to a step gain having a gain whose gain changes by a predetermined value when the signal level of a received signal exceeds a predetermined level A control type, a radio receiver of an automatic gain control circuit such as a continuous gain control type whose gain varies with the signal level of a received signal, a radio receiving method, and a recording medium.

Background technique

Radio receivers like current pagers are equipped with automatic gain control (hereinafter abbreviated as "AGC") circuits, and intermodulation desensitization (hereinafter abbreviated as "IM") is improved by controlling the gain of the radio receiver features and features due to excess input.

Here is a brief description of IM. "IM (Intermodulation Desensitization)" means a phenomenon that, when several waves having a specific frequency relationship are input to a radio receiver, due to distortion of semiconductor devices such as transistors, diodes, etc. Noise is generated in the receive frequency band.

Also, as a characteristic of noise generated by this IM, it is known that when the level of an interference wave having an n-th order IM relationship rises, the noise level generated in the reception band of the receiver becomes 1:n. For example, in the case where two kinds of interference waves having a frequency corresponding to the third-order IM are input to the receiver, when the interference wave input increases by 1 [dB], the noise level generated in the receiving frequency band of the receiver increases 3[dB] higher. In contrast, if the gain of the receiver is attenuated by 1[dB], then the desired wave is attenuated by 1[dB] and the noise generated by the 3rd order IM is attenuated by 3[dB]. Therefore, the desired wave level can be increased by 2[dB] compared to the noise level generated by the 3rd order IM, instead of the level before the gain is reduced by 1[dB].

In this way, in the IM area, the desired wave and interference wave of a call can be improved by controlling (attenuating) the gain of the receiver.

In the prior art, there are two types of AGC circuits, namely, the "continuous gain control type" whose gain control amount varies with the signal level input to the radio receiver, and the "continuous gain control type" when the signal level exceeds a predetermined level. "Gain control type" whose gain is controlled by a predetermined constant level.

First, a prior art radio receiver having a continuous gain control type AGC circuit will be described below with reference to FIG. 19. FIG. FIG. 19 shows the structure of a prior art radio receiver (first comparative example) having a continuous gain control type AGC circuit.

In FIG. 19, the radio receiver in the first comparative example is configured to include an antenna 501, a low-noise signal amplifier (LNA) 502, a local oscillator circuit 503, a frequency converter circuit 504, an electric field intensity detector 505, and a gain control circuit 506 .

An antenna 501 receives a signal transmitted from a base station (not shown). A low noise signal amplifier (LNA) 502 amplifies a signal received through the antenna 501 . The frequency converter circuit 504 performs frequency conversion by multiplying the signal amplified by the low noise signal amplifier 502 and the signal supplied from the local oscillator circuit 503 . The electric field intensity detector 505 changes the voltage of the output signal GC5 according to the signal level of the frequency-converted intermediate frequency signal IF. The gain control circuit 506 changes the control level of the gain in response to the output signal GC5 from the electric field strength detector 505 .

If the level of the signal input to the antenna 501 changes, the signal level of the intermediate frequency signal IF frequency-converted by the frequency converter circuit 504 also changes accordingly. The voltage of the output signal GC5 of the electric field strength detector 505 changes according to the change of the level of the intermediate frequency signal IF, and then the gain control amount of the gain control circuit 506 also changes with such a change.

Next, referring to FIG. 21, a prior art radio receiver having a stepped gain control type AGC circuit will be described. FIG. 21 shows the configuration of a radio receiver (second comparative example) having a step gain control type automatic gain control circuit in the prior art.

In FIG. 21, the radio receiver in the second comparative example is configured to include an antenna 601, a low-noise signal amplifier (LNA) 602, a local oscillator circuit 603, a frequency converter circuit 604, an electric field intensity detector 605, and a gain control circuit 606 .

Here, the antenna 601, the low-noise signal amplifier 602, the local oscillator circuit 603, and the frequency converter circuit 604 have the same functions as those in the first comparative example (FIG. 19). When the signal level of the intermediate frequency signal IF frequency-converted by the frequency converter circuit 504 exceeds a predetermined value, the electric field strength detector 605 changes the signal GC6 and outputs it. The operation state (ON state/OFF state) of the gain control circuit 606 is switched by a signal GC6 from the electric field intensity detector 605 . In this case, the gain control amount controlled by the gain control circuit 606 is a constant value regardless of the level of the signal input from the antenna 601 .

However, in the above-mentioned radio receiver in the prior art, the setting of the radio receiver is determined by searching for a compromise point between the IM characteristic and the electric field change characteristic.

First, the relationship among the electric field strength level threshold value for starting AGC operation, the IM characteristic, and the sensitivity threshold value for AGC operation in a conventional radio receiver having a continuous gain control type AGC circuit (first comparative example) will be described below . FIG. 20 is a graph showing the correlation among the electric field strength level threshold value for starting AGC operation, the IM characteristic, and the sensitivity threshold value for AGC operation in the continuous gain control type AGC circuit.

As described above, as a feature of the continuous gain control type AGC circuit, it is possible to tabulate the change of the gain control amount with the change of the signal level. However, if the signal level changes at a speed so high as to exceed the follow-up speed at which the AGC circuit operates against a change in the signal level, if the electric field strength of the radio signal changes more than between the sensitivity and the operation start point of the AGC circuit The difference between (the sensitivity critical value of AGC operation), then, the electric field strength drops below the sensitive point. Therefore, it is necessary to ensure a sufficient sensitivity threshold for AGC operation.

Therefore, if the threshold value of the electric field intensity level for starting AGC operation is set higher, since a larger sensitivity boundary value of AGC operation can be ensured, the electric field change of AGC operation against the desired wave becomes stronger, but it can be improved by the AGC circuit The IM area has shrunk. In addition, in order to improve the IM feature, if the threshold value of the electric field intensity level for starting the AGC operation is set at a low level, then the receivable calling area under the IM feature is enlarged, however, since the sensitivity threshold value of the AGC operation becomes smaller , the AGC operation against changes in the electric field required for the wave also becomes weaker. As such, in a continuous gain control type AGC circuit whose gain follows electric field variation, setting the electric field intensity level threshold at which AGC operation starts must take into account both the IM characteristic and the electric field variation characteristic.

Next, the interaction among the electric field strength level threshold value for starting AGC operation, the IM characteristic, and the sensitivity threshold value for AGC operation in a conventional radio receiver having a stepped gain control type AGC circuit (second comparative example) will be described below. relation.

In the staged gain control type AGC circuit, if a large gain is controlled at a certain moment, a large noise is generated during gain control (at the time of switching). Therefore, generally speaking, the electric field detection and gain conversion are completed in the signal synchronization part, but the gain control amount is not converted in the data interval (data interval), therefore, while the gain is fixed at a constant gain control amount Implement the receive operation. In this way, the stepped gain control type AGC circuit cannot follow the electric field variation in the data interval. Then, if the magnitude of change in the electric field strength of the radio signal exceeds the difference between the electric field strength level threshold for starting the AGC operation and the sensitivity of the AGC operation (the sensitivity threshold for the AGC operation), then the AGC circuit makes a decision when performing electric field detection. The signal level is operated under such a judgment of very strong electric field. In this case, since the electric field strength drops below a sensitive level with AGC operation in the data interval, it is impossible to receive the transmitted data. Therefore, in the stepped gain control type AGC circuit, it is also necessary to ensure a sufficient sensitivity threshold for AGC operation.

Fig. 22 is a graph showing the correlation among the electric field strength level threshold value for starting AGC operation, the gain control amount and the calling rate in the stepped gain control type AGC circuit. In FIG. 22, a call rate of 80% is set as a sensitive point.

As the gain reduction is improved by increasing the gain controller, the sensitive point of AGC operation is also decreased. For example, as shown in Fig. 22, consider the case that when the AGC circuit is in the "OFF" state (when not operating), if the static sensitivity is 20 [dBμV/m], then the gain control amount Set to 10[dB] and 15[dB] respectively. If the gain control amount is set to a small value, such as 10[dB], then the static sensitivity of the AGC operation will drop by 10[dB] and become 30[dBμV/m], and if the gain control amount is set to a large value, For example, 15[dB], then, the static sensitivity of AGC operation drops by 15[dB] and becomes 35[dBμV/m]. In addition, in the case where the electric field strength level threshold for starting the AGC operation in the electrostatic field is set to 40 [dBμV/m], if the gain control amount is set to 10 [dB], then the sensitivity critical value of the AGC operation is 10[dB], and if the gain control amount is set to 15[dB], then the sensitivity threshold of AGC operation is 5[dB]. In this way, under the condition that the electric field intensity level thresholds for starting the AGC operation are equal, the larger the AGC gain control amount is set, the smaller the sensitivity threshold value of the AGC operation will decrease.

Fig. 23 is a graph showing the correlation among electric field intensity level threshold value for starting AGC operation, gain control amount and call receivable area under IM characteristic in the stepped gain control type AGC circuit.

If it is assumed that the electric field strength level thresholds for starting AGC operation are equal, then, if the gain control amount increases, the service area where IM interference exists expands (from AS2 to AS3), and if the gain control amount decreases, the IM The service area that can be called by the AGC circuit under the characteristic is reduced. In this way, in the stepped gain control type AGC circuit, the setting of the AGC circuit must also be set in consideration of both the sensitivity threshold and the IM characteristic of the AGC operation.

As described above, regardless of the structure of the AGC circuit, the setting of the AGC circuit must be realized by finding a compromise point thereof in consideration of both the sensitivity threshold of the AGC operation and the IM characteristic.

It is known that, in general, the faster the transmission data rate of the transmitted signal increases, the more the sensitivity of the radio receiver decreases. Therefore, if the transmission conditions such as the transmission data speed of the signal, etc. are different, the optimum value of the AGC setting value is also different. However, for example, in a radio receiver whose transmission conditions for receiving its signal format, for example, the transmission data speed of the transmission signal, etc., change into two types or more types of signals during transmission, like a FLEX system pager Or FLEX-TD system pager, the same setting is applied to the AGC circuit regardless of the transmission condition of the signal. In other words, the optimum setting of the AGC circuit differs depending on the radio wave environment in which the radio receiver is placed. However, in the prior art, no means for setting the AGC circuit according to the transmission conditions is provided to the radio receiver, and therefore, it is not always possible to set the AGC circuit optimally.

Contents of the invention

The present invention has been made after considering the above-mentioned circumstances of the prior art. The object of the present invention is to provide a radio receiver that can obtain the optimum setting of the AGC circuit according to the radio wave environment in which the radio receiver is located, and can control the gain so that the signal quality of the received signal can be adjusted in the IM characteristic or The variation of the electric field is optimized to improve the communication quality; the invention also provides a radio receiving method and a recording medium.

In order to achieve the above object, the radio receiver according to the first aspect of the present invention includes: gain control means for controlling the gain of the radio receiver; electric field strength detection means for detecting the electric field strength of the received signal; error rate measurement means for for measuring the error rate of the received signal; and threshold setting means for setting the electric field strength level threshold according to the error rate of the measured received signal, wherein when the electric field strength detected by the electric field strength detection means reaches the electric field strength level threshold , the electric field intensity detecting means causes the gain control means to start a gain control operation.

Furthermore, the radio receiver for receiving a signal having a signal format transmitted while changing the transmission condition to two types or more according to the 2nd aspect of the present invention includes gain control means for controlling radio gain of the receiver; electric field strength detection means for detecting the electric field strength of the received signal; and threshold setting means for setting the electric field strength level threshold according to the transmission condition of the received signal, wherein when the electric field strength detected by the electric field strength detection means When the electric field strength level threshold is reached, the electric field strength detection means causes the gain control means to start a gain control operation.

A radio receiver for receiving a signal having a signal format transmitted while changing a transmission condition into two types or more types according to a 3rd aspect of the present invention includes gain control means for controlling the radio receiver gain; gain control amount setting means for setting the gain control amount of the gain control means according to the transmission condition of the received signal; and control means for causing the gain control means to change the gain according to the gain control amount.

In the radio receiver according to the fourth aspect, the gain control means is of a stepped gain control type which changes the gain by a predetermined value when the signal level of the received signal exceeds a predetermined level.

In the radio receiver according to the fifth aspect, the gain control means is of a continuous gain control type which changes the gain in accordance with the signal level of the received signal.

In the radio receiver according to the sixth aspect, the threshold setting means determines the direction of change of the threshold value of the electric field intensity level in subsequent reception based on the measurement result of the error rate measuring means in current reception and the measurement result of the error rate measuring means in previous reception and/or change amount.

In the radio receiver according to the seventh aspect, the threshold setting means is based on the measurement result of the error rate measuring means in the current reception, the measurement result of the error rate measuring means in the previous reception, the electric field intensity level threshold set in the current reception, and the previous The setting value of the threshold value of the electric field strength level in the first reception determines the direction and/or amount of change of the threshold value of the electric field strength level in the subsequent reception.

In the radio receiver according to the eighth aspect, further comprising electric field strength level threshold range setting means for setting an available setting range of the electric field strength level threshold defined by the maximum value and the minimum value.

In the radio receiver according to the ninth aspect, when the threshold value of the electric field intensity level is larger than the maximum value of the available setting range, or smaller than the minimum value thereof, and the measurement result of the error rate measuring device is smaller than a predetermined value, the threshold value setting means does not change the electric field Setting of intensity level threshold.

In the radio receiver according to the tenth aspect, further comprising storage means for storing the measurement result of the error rate measuring means in the previous reception and updating the error rate measuring means with the measurement result of the error rate measuring means in the current reception. The measurement results in the second reception, save the setting value of the electric field strength level threshold in the previous reception and update the setting value of the electric field strength level threshold in the previous reception with the electric field strength level threshold set in the current reception , and save the electric field strength level threshold set in the subsequent reception and update the electric field strength level threshold set in the subsequent reception with the electric field strength level threshold set in the current reception by the electric field strength level threshold setting device.

The radio receiver according to the eleventh aspect includes: gain control means for controlling the gain of the radio receiver; error rate measuring means for measuring an error rate of a received signal; gain control amount setting means for controlling the gain according to the error rate setting a gain control amount of the gain control means; and control means for causing the gain control means to change the gain according to the gain control amount, wherein the gain control amount setting means is based on a measurement result of the error rate measuring means in current reception and the error rate measuring means From the measurement results in the previous reception, the direction of change and/or the amount of change in the gain control amount in the subsequent reception is determined.

The radio receiver according to the twelfth aspect includes: gain control means for controlling the gain of the radio receiver; error rate measuring means for measuring an error rate of a received signal; gain control amount setting means for controlling the gain according to the error rate The gain control amount of the gain control means is set; and the control means is used to make the gain control means change the gain according to the gain control amount, wherein the gain control amount setting means is based on the measurement result of the error rate measurement means in the current reception, the error rate measurement means The measurement result in the previous reception, the gain control amount set in the current reception, and the set value of the gain control amount in the previous reception determine the change direction and/or change amount of the gain control amount in the subsequent reception.

In the radio receiver according to the thirteenth aspect, further comprising gain control amount range setting means for setting an available setting range of the gain control amount defined by the maximum value and the minimum value.

In the radio receiver according to the 14th aspect, when the gain control amount is larger than a maximum value of an available setting range, or smaller than a minimum value thereof, and the measurement result of the error rate measuring means is smaller than a predetermined value, the gain control amount setting means does not change the gain Control volume settings.

The radio receiver according to the fifteenth aspect, further comprising storage means for storing the measurement result of the error rate measuring means in the previous reception and updating the measurement result of the error rate measuring means in the current reception for the previous time. The measurement result during reception, saves the set value of the gain control amount in the previous reception and updates the set value of the gain control amount in the previous reception with the gain control amount used in the current reception, and saves the setting in the subsequent reception The gain control amount and the gain control amount set in the current reception by the gain control amount setting means update the gain control amount set in the subsequent reception.

In the radio receiving method for a radio receiver according to the 16th aspect of the present invention, wherein the radio receiver includes: gain control means for controlling the gain of the radio receiver; electric field strength detection means for detecting a received signal electric field strength; and error rate measuring means for measuring the error rate of the received signal, the method comprising the steps of: an error rate measuring step for measuring the error rate in the receiving step by the error rate measuring means; threshold setting a step of setting an electric field strength level threshold based on the measured error rate of the received signal; and a first control step of causing the gain control means to start a gain control operation when the electric field strength detected by the electric field strength detecting means reaches the electric field strength level threshold.

The radio receiving method according to the seventeenth aspect further includes the following steps: a receiving step, receiving at a set electric field strength level threshold; wherein the threshold setting step is based on the measurement result of the error rate measuring device in current reception and the error rate in previous reception The measurement results of the measuring means determine the direction and/or amount of change of the electric field strength level threshold in subsequent receptions.

The radio receiving method according to the eighteenth aspect further includes the following steps: a receiving step, receiving at the set electric field strength level threshold; wherein the threshold setting step is based on the measurement result of the error rate measuring device in current reception, the error rate in previous reception The measurement result of the measuring device, the electric field strength level threshold set in the current reception and the setting value of the electric field strength level threshold in the previous reception determine the change direction and/or change amount of the electric field strength level threshold in subsequent reception.

The wireless receiving method according to the nineteenth aspect further includes a threshold range setting step of setting an available setting range of the electric field intensity level threshold defined by a maximum value and a minimum value.

In the radio receiving method according to the 20th aspect, when the electric field strength level threshold value is larger than the maximum value of the usable setting range, or smaller than the minimum value thereof, and the measurement result of the error rate measuring means is smaller than the predetermined value, the threshold value setting step does not change Setting of electric field strength level threshold.

The radio receiving method according to the 21st aspect further includes a storing step of storing the measurement result of the error rate measuring device in the previous reception and updating the measurement result of the error rate measuring device in the previous reception with the measurement result of the error rate measuring device in the current reception. The measurement result, save the set value of the electric field strength level threshold in the previous reception and update the set value of the electric field strength level threshold in the previous reception with the electric field strength level threshold set in the current reception, and save it in The electric field strength level threshold set in the subsequent reception and the electric field strength level threshold set in the current reception by the threshold setting means update the electric field strength level threshold set in the subsequent reception.

Furthermore, the radio receiving method for a radio receiver according to the 22nd aspect of the present invention, wherein the radio receiver includes: gain control means for controlling the gain of the radio receiver; and error rate measuring means for measuring The error rate of the received signal, the method includes the following steps: a gain control amount setting step, setting the gain control amount of the gain control device according to the measurement result of the error rate measurement device; a control step, making the gain control device change the gain according to the gain control amount; a receiving step of receiving at the set gain control amount; and an error rate measuring step of measuring an error rate received in the receiving step by the error rate measuring means; The measurement result of the error rate measuring device and the measurement result of the error rate measuring device in the previous reception determine the change direction and/or change amount of the gain control amount in the subsequent reception.

A radio receiving method according to claim 23, wherein said radio receiver includes: gain control means for controlling a gain of the radio receiver; and error rate measuring means for measuring an error rate of a received signal, said method comprising the following Step: a gain control amount setting step, setting the gain control amount of the gain control device according to the measurement result of the error rate measuring device; a control step, making the gain control device change the gain according to the gain control amount; a receiving step, performing on the set gain control amount receiving; and an error rate measuring step of measuring an error rate received in the receiving step by the error rate measuring device; and wherein the gain control amount setting step is based on the measurement result of the error rate measuring device in the current reception, the previous The measurement results during reception, the gain control amount set in the current reception and the set value of the gain control amount in the previous reception determine the change direction and/or change amount of the gain control amount in the subsequent reception.

The radio receiving method according to the 24th aspect further includes a gain control amount range setting step of setting an available setting range of the gain control amount defined by a maximum value and a minimum value.

In the radio receiving method according to claim 25, the gain control amount setting step does not change the gain when the gain control amount is larger than a maximum value of an available setting range, or smaller than a minimum value thereof, and the measurement result of the error rate measuring means is smaller than a predetermined value. Control volume settings.

The radio receiving method according to the twenty-sixth aspect of the present invention further includes a storing step for storing the measurement result of the error rate measuring device in the previous reception and updating the error rate measuring device with the measurement result of the error rate measuring device in the current reception. The measurement result in the second reception, save the set value of the gain control amount in the previous reception and use the gain control amount in the current reception to update the set value of the gain control amount in the previous reception, and save it in the subsequent reception The set gain control amount and the gain control amount set in the current reception by the gain control amount setting means update the gain control amount set in the subsequent reception.

A radio receiving method for a radio receiver according to a 27th aspect of the present invention includes the steps of: a threshold setting step of setting an electric field intensity level threshold according to a transmission condition of a received signal to start a gain control operation of the gain control means; and A first control step, when the electric field strength detected by the electric field strength detection device reaches the electric field strength level threshold value, the gain control device is made to start a gain control operation, wherein the radio receiver includes: a gain control device for controlling radio reception and electric field strength detecting means for detecting the electric field strength of the received signal, and receiving a signal having a signal format transmitted while changing the transmission condition to two types or more types.

A radio receiving method for a radio receiver according to a twenty-eighth aspect of the present invention includes the steps of: a gain control amount setting step of setting the gain control amount of the gain control means according to the transmission condition of the received signal; and a control step of making the gain control The device changes the gain according to the gain control amount, wherein the radio receiver includes gain control means for controlling the gain of the radio receiver, and receives a signal having transmission while changing the transmission condition to two types or more format signal.

According to the radio receiver stated in said 1st, 4th, 5th, 6th, 7th, 8th, 9th, 10th aspects of the present invention, stated in said 16th, 17th, 18th, 19th, 20th, 21st aspects of the present invention The radio receiving method, the electric field strength level threshold value of the start AGC operation of the gain control operation of the gain control device is started by the electric field strength level threshold value setting device of the start AGC operation (start AGC operation electric field Intensity level threshold setting step) is set. In the first control means (first control step), the gain control means is caused to start the gain control operation when the electric field intensity detected by the electric field intensity detection means reaches the electric field intensity level threshold for starting the AGC operation.

In particular, according to the radio receiver set forth in said fourth aspect, the gain control means is of a stepped gain control type, and changes the gain by a predetermined value when the signal level of the received signal exceeds a predetermined level. In particular, according to the radio receiver set forth in said fifth aspect, the gain control means is of a connection gain control type, and changes the gain in accordance with the signal level of the received signal.

In this way, according to the present invention, since the threshold value of the electric field strength level for starting the AGC operation is set according to the measurement result of the error rate of the received signal, the threshold value of the electric field strength level for starting the AGC operation optimally can be set to suit The radio wave environment in which the radio receiver is located, that is, the reception environment in which the signal is received, and may also be in an environment characterized by IM characteristics or electric field changes, for example, in an environment where strong IM interference signals exist, or where the electric field strength changes strongly Under the environment, the gain control of the gain control device is obtained to optimize the signal quality of the received signal. As a result, the communication quality in mobile radio communication can be considerably improved.

Here, for example, as specific examples of the structure of the first control device, the following situations can be considered. As a first specific structure, there is provided comparing means for comparing the electric field strength detected by the electric field strength detecting means with a reference strength level, and then converting and setting the reference strength level of the comparing means according to the error rate measurement result. As a second specific structure, there is provided a variable gain amplifier for amplifying a received signal with a predetermined gain and transmitting it to the electric field strength detecting device, and then changing and setting the predetermined gain of the variable gain amplifier according to the error rate measurement result . Furthermore, as a third specific structure, there is provided conversion means for converting the output of the electric field intensity detection means into a voltage level at a predetermined rate, and then, based on the error rate measurement result, the predetermined rate of the conversion means is converted and set.

Especially, according to the radio receiver stated in said 6th aspect and the radio receiving method stated in said 17th aspect, in the electric field strength level threshold setting means for starting AGC operation (the electric field strength level threshold for starting AGC operation In the setting step), the direction of change and/or the amount of change of the threshold value of the electric field strength level at which the AGC operation is started in the subsequent reception is based on the measurement result of the error rate measuring device (error rate measuring step) in the current reception and the error rate measuring device Determined by the measurement results in the previous reception.

For example, if the error rate in the current reception is smaller than the error rate in the previous reception, then, since the error rate has been improved, the direction of change of the electric field strength level threshold for starting the AGC operation in the subsequent reception can be maintained in the same direction as in the previous reception. The direction of change of the electric field strength level threshold for starting the AGC operation in the previous reception is the same, and if the error rate in the current reception is larger than that in the previous reception, then, since the error rate has deteriorated, the The direction of change of the threshold value of the electric field strength level for starting the AGC operation in subsequent reception is switched to the direction opposite to the direction of change of the threshold value of the electric field strength level for starting the AGC operation in the previous reception. Therefore, since the threshold value of the electric field strength level for starting the AGC operation can be set by appropriately determining the changing direction of the threshold value of the electric field strength level for starting the AGC operation to be set subsequently, it is possible to set the threshold value of the electric field strength level for starting the AGC operation in an environment where there is a strong IM interference signal or where the electric field The setting of the threshold value of the electric field strength level for optimally starting AGC operation under an environment with strong changes in strength.

For example, even if the error rate is high, if the error rate change amount determined by the difference between the error rate in the current reception and the error rate in the previous reception or other similar parameters is lower than a predetermined value, then AGC is started The change amount of the threshold value of the electric field strength level for operation is relatively increased, and if the change amount of the error rate exceeds a predetermined value, the change amount of the threshold value of the electric field strength level for starting AGC operation is relatively reduced. Therefore, it is possible to speed up the convergence of the electric field strength level threshold for starting the AGC operation to the electric field strength level threshold for starting the AGC operation optimally.

In addition, if, for example, when the error rate exceeds a predetermined value, the threshold value of the electric field strength level for starting the AGC operation returns to a predetermined initial value, then, when the setting of the threshold value of the electric field strength level for starting the AGC operation is obviously out of bounds, appropriate measures can be taken Precautions.

In particular, according to the radio receiver stated in said 7th aspect and the radio receiving method stated in said 18th aspect, in the electric field strength level threshold setting means for starting AGC operation (the electric field strength level threshold for starting AGC operation In the setting step), the direction of change and/or the amount of change of the threshold value of the electric field intensity level at which the AGC operation is started in the subsequent reception is based on the measurement result of the error rate measurement device (error rate measurement step) in the current reception, the error rate measurement device Determined by the measurement result in the previous reception, the threshold value of the electric field strength level for starting the AGC operation set in the current reception, and the set value of the threshold value of the electric field strength level for starting the AGC operation in the previous reception.

For example, in the case where the error rate in the current reception is smaller than the error rate in the previous reception (the error rate has been improved), when the electric field strength level threshold for starting the AGC operation in the current reception is larger than that in the previous reception When starting the electric field strength level threshold for AGC operation, increase the electric field strength level threshold for starting AGC operation in the subsequent reception, and when the electric field strength level threshold for starting AGC operation in the current reception is smaller than that in the previous reception When the threshold value of the electric field strength level for starting the AGC operation is lowered, the threshold value of the electric field strength level for starting the AGC operation in the subsequent reception is made smaller. Conversely, in the case where the error rate in the current reception is greater than the error rate in the previous reception (the error rate has become worse), when the electric field strength level threshold for starting the AGC operation in the current reception is greater than that in the previous reception When starting the electric field strength level threshold for AGC operation, set the electric field strength level threshold for starting AGC operation in subsequent reception to be smaller, and when the electric field strength level threshold for starting AGC operation in current reception is smaller than the previous When the threshold value of the electric field strength level for starting the AGC operation in the first reception is lowered, the threshold value of the electric field strength level for starting the AGC operation in the subsequent reception is increased. Therefore, since the electric field intensity level threshold value for starting AGC operation can be set by more appropriately determining the change direction of the electric field intensity level threshold value for starting AGC operation to be set subsequently, it is possible to set the threshold value in a strong electric field intensity IM environment or in which an electric field occurs Sets the threshold electric field strength level optimal to start AGC operation under strongly changing environment.

Especially, according to the radio receiver stated in said 8th aspect and the radio receiving method stated in said 19th aspect, preferably, the electric field strength level threshold value for starting AGC operation defined by the maximum value and the minimum value The available setting range should be set by the electric field strength level threshold range setting means for starting AGC operation (the electric field strength level threshold range setting step for starting AGC operation). Furthermore, according to the radio receiver set forth in said 10th aspect and the radio receiving method set forth in said 21st aspect, in the electric field strength level threshold value setting means for starting AGC operation (the electric field strength level threshold value setting means for starting AGC operation In step), preferably, when the electric field strength level threshold value that starts AGC operation is greater than the maximum value of usable setting range, or is less than its minimum value, and when the measurement result of error rate measuring device is less than predetermined value, do not change the start AGC operation Setting of electric field strength level threshold. Therefore, in the case where the set value of the threshold value of the electric field strength level for starting the AGC operation is set to the maximum value or the minimum value, it is possible to prevent the electric field strength level for starting the AGC operation from being changed unnecessarily even if the error rate is sufficiently small Threshold for the set value of the situation occurs.

Especially, according to the radio receiver stated in said 10th aspect and the radio receiving method stated in said 21st aspect, preferably, the storage means (storage step) should be updated/ Save the measurement result of the error rate measurement device in the current reception as the measurement result of the error rate measurement device in the previous reception, update/save the electric field strength level threshold value set in the current reception to start the AGC operation as the previous measurement Start the setting value of the electric field strength level threshold value of AGC operation, and update/save the electric field strength level threshold value setting device of starting AGC operation to set the electric field strength level threshold value of starting AGC operation set in the current reception as setting in subsequent reception The electric field strength level threshold to start AGC operation. Therefore, more efficient processing can be performed in the electric field strength level threshold range setting means for starting AGC operation (the electric field strength level threshold range setting step for starting AGC operation).

According to the radio receiver stated in the 4th, 11, 12, 13, 14, and 15 aspects of the present invention, and the radio receiving method stated in the 22nd, 23, 24, 25, and 26 aspects, the gain of the gain control device The control amount is set by the gain control amount setting means (gain control amount setting step) based on the measurement result of the error rate measuring means. In the control means (control step), the gain control means is caused to change the gain in accordance with the gain control amount.

In particular, according to the radio receiver set forth in said 4th aspect, the gain control means is of a stepped gain control type, and changes the gain by a predetermined value when the signal level of the received signal exceeds a predetermined level.

In this way, according to the present invention, since the gain control amount can be set according to the measurement result of the error rate of the received signal, an optimum gain control amount can be set to suit the radio wave environment in which the radio receiver is located, that is, The receiving environment of the received signal, and also under the environment of IM characteristic or electric field change characteristic, for example, under the environment of strong electric field intensity IM, or under the environment in which electric field changes strongly, the gain control of the gain control device can be obtained to optimize Optimize the signal quality of the received signal. As a result, the communication quality in mobile radio communication can be considerably improved.

Here, for example, as specific examples of the structures of the gain control means and the second control means, the following situations can be considered. As a first specific structure, here, signal amplifying means for amplifying the received signal and distribution means for distributing the received signal received through the antenna to the signal amplifying means and other signal paths are provided to the gain control means, and then, by the first The second control device changes the distribution ratio of the distribution device to the signal amplification device according to the measurement result of the error rate. Here, "other signal paths" are, for example, routes from the antenna to the ground.

Furthermore, as a second specific structure, the gain control means is provided with signal amplifying means whose gain is controlled by an output voltage conversion circuit whose output voltage can be switched, and the output voltage of the output voltage conversion circuit is controlled by the second control means according to the error rate to change the measurement results. In addition, as a third specific structure, the signal amplifying means including a current source having a power conversion function is provided to the gain control means, and the second control means changes and sets the signal from the signal amplifying means according to the measurement result of the error rate, The current value of the current source with current conversion function.

In particular, according to the radio receiver set forth in said 11th aspect and the radio receiving method set forth in said 22nd aspect, in the gain control amount setting means (gain control amount setting step), in subsequent reception the gain control amount The change direction and/or change amount of is determined according to the measurement result of the error rate measuring device (error rate measuring step) in the current reception and the measurement result of the error rate measuring device in the previous reception.

For example, if the error rate in the current reception is smaller than the error rate in the previous reception, then, since the error rate is improved, the change direction of the gain control amount in the subsequent reception can be kept the same as that in the previous reception. The change direction is the same, and if the error rate in the current reception is greater than the error rate in the previous reception, then, because the error rate has become worse, the change direction of the gain control amount in the subsequent reception can be switched to the gain in the previous reception. The change direction of the control quantity is in the opposite direction. Therefore, since the gain control amount can be set by appropriately determining the change direction of the gain control amount to be set subsequently, the optimum gain control amount can be obtained under an environment of strong electric field intensity IM or an environment in which the electric field is strongly changed setting.

In addition, for example, even if the error rate is high, when the amount of change in the error rate determined by the difference between the error rate in the current reception and the error rate in the previous reception, or other similar parameters is lower than a predetermined value, the gain The change amount of the control will also increase relatively, and when the change amount of the error rate exceeds a predetermined value, the change amount of the gain control will relatively decrease. Therefore, it is possible to speed up the convergence of the gain control amount to the optimum gain control amount.

In addition, for example, if the gain control amount is returned to a predetermined initial value when the error rate exceeds a predetermined value, appropriate preventive measures can be taken when the setting of the gain control amount is obviously out of bounds.

In particular, according to the radio receiver stated in the twelfth aspect and the radio reception aspect stated in the 23rd aspect, in the gain control amount setting means (gain control amount setting step), the gain control amount in subsequent reception The change amount of is based on the measurement result of the error rate measuring device (error rate measuring step) in the current reception, the measurement result of the error rate measuring device in the previous reception, the gain control amount set in the current reception, and the gain control amount set in the previous measurement. It is determined by the setting value of the medium gain control amount.

For example, in the case where the error rate in the current reception is smaller than the error rate in the previous reception (the error rate is improved), when the gain control amount in the current reception is larger than the gain control amount in the previous reception, increase The gain control amount in the subsequent reception is large, and when the gain control amount in the current reception is smaller than the gain control amount in the previous reception, the change in the gain control amount in the subsequent reception is made smaller. Conversely, in the case where the error rate in the current reception is larger than the error rate in the previous reception (the error rate has become worse), when the gain control amount in the current reception is larger than the gain control amount in the previous reception, the The gain control amount in the subsequent reception is set smaller, and when the gain control amount in the current reception is smaller than the gain control amount in the previous reception, the gain control amount in the subsequent reception is increased. Therefore, since the gain control amount can be set by more appropriately determining the change direction of the gain control amount to be set subsequently, an optimum gain control amount can be set in an environment of a strong electric field IM or an environment in which the electric field changes strongly.

Especially, according to the radio receiver stated in the 13th aspect and the radio receiving method stated in the 24th aspect, preferably, the usable setting range of the gain control amount defined by the maximum value and the minimum value should be defined by the gain control amount range setting device (gain control amount range setting step) to set. Furthermore, according to the radio receiver stated in the 14th aspect and the radio receiving method stated in the 25th aspect, in the gain control amount setting means (gain control amount setting step), when the gain control amount is larger than the available setting range When the maximum value of , or less than its minimum value, and the measurement result of the error rate measuring device is less than the predetermined value, the setting of the gain control amount will not be changed. Therefore, in the case where the set value of the gain control amount is set to the maximum value or the minimum value, when the error rate is sufficiently low, it is possible to prevent the occurrence of a situation where the set value of the gain control amount is changed unnecessarily.

Especially, according to the radio receiver recited in said 15th aspect and the radio receiving method recited in said 26th aspect, preferably, the storage means (storage step) should be updated every reception or every predetermined number of receptions / Save the measurement result of the error rate measuring device in the current reception as the measurement result of the error rate measuring device in the previous reception, update/save the gain control amount set in the current reception as the setting of the gain control amount in the previous reception fixed value, and update/save the gain control amount set by the gain control amount setting means in the current reception as the gain control amount set in the subsequent reception. Therefore, more efficient processing can be performed in the gain control amount setting means (gain control amount setting step).

Furthermore, according to the radio receiver set forth in the 2nd, 4th, and 5th aspects of the present invention, and the radio receiving method set forth in the 27th aspect, when receiving the When two types or more types of signals of the signal format transmitted simultaneously, the electric field intensity level threshold value setting means for starting the AGC operation (the electric field intensity level threshold value setting step for starting the AGC operation) starts according to the transmission condition setting of the signal An electric field strength level threshold for AGC operation to initiate gain control operation of the gain control means. In the first control means (first control step), the gain control means is caused to start the gain control operation when the electric field intensity detected by the electric field intensity detection means reaches the electric field intensity level threshold for starting the AGC operation.

As a radio receiver that receives a signal having a signal format that is transmitted while changing transmission conditions such as transmission data speed into two types or more types, such radio receivers are, for example, FLEX system pagers and FLEX-TD system pagers, etc. In such a radio receiver, since the threshold value of the electric field strength level at which the AGC operation is started can be set to suit the transmission condition of the signal, the optimum gain control of the gain control device can be obtained to satisfy the transmission condition of the signal, as a result, in The communication quality in mobile radio communication can be considerably improved.

In addition, according to the radio receiver stated in the 3rd and 4th aspects of the present invention, and the radio receiving method stated in the 28th aspect, when receiving a signal having a transmission condition such as a transmission data speed changed into two type or more types of signals in the signal format transmitted simultaneously, the gain control amount of the gain control means is set by the gain control amount setting means (gain control amount setting step) according to the transmission condition of the signal. In the control means (control step), the gain control means is caused to change the gain in accordance with the gain control amount.

For example, when receiving a signal having a signal format that is transmitted while changing transmission conditions such as transmission data speed into two types or more types, radio reception such as a FLEX system pager, a FLEX-TD system pager, etc. In the controller, the gain control amount can be set to suit the sending conditions of the signal. Therefore, the optimum gain control of the gain control device can be obtained to satisfy the signal transmission conditions. As a result, the communication quality in mobile radio communication can be considerably improved.

Description of drawings

FIG. 1 is a block diagram showing the structure of a radio receiver according to a first embodiment of the present invention;

FIG. 2 is a block diagram showing a specific structure of an electric field intensity detector in the radio receiver according to the first embodiment;

3 is a flowchart showing an electric field strength level threshold setting method (first example) for starting an AGC operation in the radio receiver according to the first embodiment;

4 is a flowchart showing an electric field strength level threshold setting method (second example) for starting an AGC operation in the radio receiver according to the first embodiment;

5 is a flowchart showing an electric field strength level threshold setting method (third example) for starting AGC operation in the radio receiver according to the first embodiment;

6 is a flowchart showing an electric field strength level threshold setting method (fourth example) for starting AGC operation in the radio receiver according to the first embodiment;

7 is a flowchart showing an electric field strength level threshold setting method (fifth example) for starting AGC operation in the radio receiver according to the first embodiment;

8 is a block diagram showing the structure of a radio receiver according to a second embodiment of the present invention;

FIG. 9 is a block diagram showing a specific structure of a gain control circuit in a radio receiver according to a second embodiment;

10 is a flowchart showing an AGC gain control amount setting method (first example) in the radio receiver according to the second embodiment;

11 is a flowchart showing an AGC gain control amount setting method (second example) in the radio receiver according to the second embodiment;

12 is a flowchart showing an AGC gain control amount setting method (third example) in the radio receiver according to the second embodiment;

13 is a flowchart showing an AGC gain control amount setting method (fourth example) in the radio receiver according to the second embodiment;

14 is a flowchart showing an AGC gain control amount setting method (fifth example) in the radio receiver according to the second embodiment;

15 is a block diagram showing the structure of a radio receiver according to a third embodiment of the present invention;

16 is a flowchart showing a method of separately setting an electric field strength level threshold for starting an AGC operation based on a signal transmission state in the radio receiver according to the third embodiment;

FIG. 17 is a block diagram showing the structure of a radio receiver according to a fourth embodiment of the present invention;

18 is a flowchart showing a method of separately setting an AGC gain control amount based on a signal transmission state in the radio receiver according to the fourth embodiment;

19 is a block diagram showing the structure of a radio receiver (first comparative example) having a continuous gain control type automatic gain control circuit in the prior art;

FIG. 20 is a graph showing the correlation among the electric field intensity level threshold value for starting AGC operation, IM characteristic, and sensitivity threshold value in AGC operation in the continuous gain control type automatic gain control circuit;

FIG. 21 is a block diagram showing the structure of a radio receiver (second comparator) having a stepped gain control type automatic gain control circuit in the prior art;

Fig. 22 is a graph showing the correlation among electric field intensity level threshold value, gain control amount, and call rate for starting AGC operation in the automatic gain control circuit of stepped gain control type; and

Fig. 23 is a graph showing the correlation among electric field strength level threshold value for starting AGC operation, gain control amount and receivable calling area in the automatic gain control circuit of stepped gain control type.

Detailed ways

Embodiments of the radio receiver, radio receiving method, and recording medium of the present invention will be described in detail in the order of the first embodiment, the second embodiment, the third embodiment, and the fourth embodiment with reference to the accompanying drawings. In describing the respective embodiments, the radio receiver and the radio receiving method according to the present invention are given in detail, but the description of the recording medium according to the present invention will be included in the following description of the radio receiving method, because thus A recording medium for recording a program causing a radio receiver to execute a radio receiving method.

[first embodiment]

FIG. 1 is a diagram showing the structure of a radio receiver according to a first embodiment of the present invention.

In FIG. 1, the radio receiver according to the first embodiment is configured to include an antenna 101, a low noise signal amplifier (LNA) 102, a local oscillator circuit (Local) 103, a frequency converter circuit (Mix) 104, an electric field Intensity detector 105 , gain control circuit 106 , signal processor section 107 , memory 108 and error rate measurement circuit 109 .

The antenna 101 receives a signal transmitted from a base station (not shown in the figure). The low noise signal amplifier 102 amplifies a signal received through the antenna 101 . The frequency converter circuit 104 performs frequency conversion by multiplying the signal amplified by the low noise amplifier 102 and the signal from the local oscillator circuit 103 .

When the electric field strength of the signal reaches the electric field strength level threshold value for starting the AGC operation according to the control parameter (signal CN1), the electric field strength detector 105 changes according to the strength of the received signal whose frequency has been converted into the intermediate frequency (IF) by the frequency converter circuit 104 The voltage of the output signal GC1. The gain control circuit 106 changes the gain control amount in response to the output signal GC1 from the electric field intensity detector 105 .

In the memory 108, the error rate measurement result in the previous reception, the set value of the threshold value of the electric field strength level for starting the AGC operation in the previous reception, the start AGC for setting the AGC in the subsequent reception during processing are stored. Other parameters of the electric field strength level threshold for operation and the electric field strength level threshold for starting AGC operation set by the above-mentioned process in subsequent reception.

The signal processor section 107 demodulates the received signal, based on the error rate data of the received signal and in automatic gain control (hereinafter abbreviated as "AGC") by comparing the data currently being received with the data stored in the memory 108 in the previous reception. The set value obtained by data comparison sets the electric field strength level threshold value for starting AGC operation, and controls the electric field strength detector 105 by providing a control parameter (signal CN1). Furthermore, the signal processor section 107 updates the error rate measurement result stored in the memory 108 in the previous reception with the error rate measurement result in the current reception, using the electric field strength level threshold value set in the current reception to start the AGC operation. Update the set value of the threshold value of the electric field strength level for starting the AGC operation in the previous reception, and update the value set in the subsequent reception with the threshold value of the electric field strength level for starting the AGC operation set by the signal processor section 107 in the current reception. Electric field strength level threshold to start AGC operation.

As described above, the electric field strength level threshold to start the AGC operation to be set in the current reception is determined by the processing performed by the signal processor section 107 in the previous reception, and stored in the memory 108 . The signal processor section 107 controls the setting of the electric field strength detector 105 by outputting the control signal CN1 based on the stored electric field strength level threshold for starting the AGC operation obtained by looking up the memory 108 .

Next, a specific structure for changing the setting of the electric field intensity detector 105 in accordance with the control signal CN1 from the signal processor section 107 will be described below with reference to FIG. 2 . FIG. 2 shows a specific structure of an electric field intensity detector in the radio receiver according to the first embodiment. In FIG. 2, the electric field intensity detector 105 is configured to include an electric field intensity detector section 111, a reference voltage switching circuit 112, and an electric field intensity level threshold switching circuit 113 for starting an AGC operation.

The electric field intensity detector section 111 detects the electric field intensity of the intermediate frequency signal IF after frequency conversion. The electric field strength detector section 111 has a feature that when the voltage output changes with the strength of a signal input to the radio receiver, the output voltage rises as the signal strength increases.

The reference voltage conversion circuit 112 converts the output voltage (the reference voltage of the electric field intensity level threshold value to start the AGC operation) according to the control signal CN1 from the signal processor section 107 .

The electric field intensity level threshold switching circuit 113 which starts the AGC operation compares the output voltage of the electric field intensity detector section 111 with the output voltage of the reference voltage switching circuit 112, and when the output voltage of the electric field intensity detector section 111 exceeds the reference voltage switching circuit 112, the signal GC1 is output to the gain control circuit 106 according to the output signal of the electric field intensity detector section 111.

In the specific structure shown in FIG. 2 , the reference voltage of the reference voltage conversion circuit 112 corresponding to the electric field strength level threshold at which the AGC operation starts is stored in the memory 108 as a control parameter. In other words, the signal processor section 107 reads, from the memory 108, a control parameter (reference voltage) corresponding to the electric field intensity level threshold value set in the previous reception to start the AGC operation, and outputs the control parameter as the control signal CN1 to The reference voltage conversion circuit 112 provided in the electric field intensity detector 105 converts the output voltage of the reference voltage conversion circuit 112 (ie, the reference voltage of the electric field intensity level threshold value conversion circuit 113 to start the AGC operation).

The output of the electric field strength detector section 111 whose output voltage changes according to the strength of the signal input to the radio receiver and the output of the reference voltage conversion circuit 112 are compared with each other by the electric field strength level threshold value conversion circuit 113 which starts the AGC operation, and When the output of the electric field strength detector section 111 is larger than the output of the reference voltage conversion circuit 112 , the signal GC1 is output from the electric field strength detector 105 to the gain control circuit 106 . In this way, in the specific structure shown in FIG. 2, it is possible to change the threshold value of the electric field strength level at which the AGC operation starts by switching the reference voltage of the reference voltage switching circuit 112.

As specific examples of changing the configuration of the electric field intensity detector 105 (first control means), in addition to the first specific configuration shown in FIG. 2 above, the following configurations can also be considered.

For example, as a second specific structure, a structure can be considered in which the output IF (intermediate frequency signal after frequency conversion) of the frequency converter circuit 104 is amplified by a variable gain amplifier, and then, the amplified signal is supplied to the electric field intensity Detector. At this time, the gain of the variable gain amplifier is changed according to the control signal CN1 from the signal processor section 107 .

Furthermore, as a third specific structure, a structure can be considered in which an electric field intensity detector and a current/voltage converter circuit for current output are arranged, and the output of the electric field intensity detector is used as the current output (that is, according to The signal level of the signal IF after the frequency conversion changes the current output). At this time, the conversion gain of the current/voltage converter circuit is changed according to the control signal CN1 from the signal processor section 107 .

For example, the error rate measurement circuit 109 is composed of a BCH code correction circuit, and calculates the error rate of the signal according to the number of corrected errors and the number of uncorrected errors of the demodulated signal.

In current mobile radio receiver systems, generally, radio signals are transmitted as BCH codes in many cases to improve communication quality. Therefore, radio receivers that receive BCH-coded radio signals are equipped with BCH code correction circuits. Therefore, the radio receiver of this embodiment also utilizes the BCH code correction circuit as the error rate measurement circuit 109 . That is to say, in the case that the error can be corrected in the BCH code correction circuit, the error rate of the signal in the signal interval can be calculated by weighting the error caused at a certain value, or counting the number of error corrections in the signal interval and the number of uncorrected errors. The number of error corrections to measure.

For example, consider a case where a word is composed of a 32-bit signal, and the error rate of the signal on a block constituting eight words (256 bits) is measured. According to the BCH code correction circuit capable of being accurate to two bits per word, errors in signals smaller than two bits per word can be identified. Furthermore, if there is an error greater than three bits per word, it is impossible to correct the error, and therefore it is impossible to identify the wrong number of bits. In this case, if the error numbers of words in which errors of more than three bits occur are uniformly determined to a specific value, then the error rate of the signal in the block can be calculated. Here, the calculation can be performed assuming that the error rate of words in which errors of more than three bits are generated is uniformly set to "3".

Now consider as an example a case where the number of error corrections is "5" and the number of uncorrected words is "1" in one block. The whole block (256 bits) error count is calculated as the value obtained by multiplying the error correction count and the uncorrected word count by the error count 3, ie, 5+3*1=8. Thus, dividing the number of errors for the entire block by the total number of bits gives the error rate of the signal in this block, ie, 8/256 = 0.03125.

In this way, the error rate of the received signal can be calculated by counting the number of error corrections and the number of uncorrected errors by the BCH code correction circuit. In the first embodiment, since the BCH code correction circuit is used as the error rate measurement circuit 109, and the setting of AGC is made by using the result of the received signal of the error rate measurement circuit 109, the reception quality can be improved.

Next, the radio receiving method in the radio receiver having the above structure according to the first embodiment will be described in detail below in order of the first example, the second example, the third example, the fourth example and the fifth example with reference to the accompanying drawings. (An example of an electric field intensity level threshold setting method for starting AGC operation using the measurement result of the received signal obtained by the error rate measurement circuit 109). In the following description, as for the correlation between the set value of the threshold value of the electric field strength level for starting the AGC operation and the threshold value of the electric field strength level for starting the AGC operation in the AGC operation, it is assumed that if the set value is smaller than small, the AGC operation is started even when the electric field value is small, whereas if the set value is large, the AGC operation is not started until the electric field value becomes large.

(first example)

FIG. 3 is a flowchart showing an electric field intensity level threshold setting method (first example) for starting AGC operation in the radio receiver according to the first embodiment. In the electric field strength level threshold setting method for starting the AGC operation of the first example, if the error rate in the current reception is smaller than the error rate in the previous reception, then the electric field strength level at which the AGC operation is started in the subsequent reception The change direction of the threshold value continues to be kept in the same direction as the change direction of the electric field strength level threshold value for starting the AGC operation in the previous reception, because the error rate can be improved in this way, and if the error rate in the current reception is greater than that in the previous reception error rate in reception, then, since the error rate has deteriorated, the change direction of the electric field strength level threshold for starting AGC operation in subsequent reception is switched to the same electric field strength level threshold value as that for starting AGC operation in previous reception The flat threshold changes in the opposite direction. In this case, the change amount of the threshold value of the electric field strength level at which the AGC operation is started is set to a constant value.

Next, each variable (parameter stored in the memory 108) used in FIG. 3 will be described. ERROR 1 is the error rate measurement result of the received signal in the previous reception, and is set to an initial value as described later when initially setting up the radio receiver. ERROR 2 is the error rate measurement result of the received signal in the current reception. START is the setting value of the threshold value of the electric field intensity level at which the AGC operation is started, and d is the change control amount of the threshold value of the electric field intensity level at which the AGC operation is started.

First, when the power of the radio receiver is received for initial setting in step S101, parameters ERROR 1, ERROR 2, START, and d are set to predetermined initial values in step S102. These steps S101 and S102 are the initial setting processing procedure in the setting operation. Steps S103 to S107 as described later are to set the electric field strength level threshold for starting AGC operation by appropriately determining the change direction of the electric field strength level threshold for starting AGC operation to be set subsequently, and when receiving has been performed a predetermined number of times The subsequent processing is performed every reception or every few receptions.

In step S103, a radio signal is received by setting the threshold value of the electric field strength level to start the AGC operation to START. In step S104, the error rate measurement circuit 109 measures the error rate of the received signal, and then stores the measurement result in ERROR 2 as the error rate currently being received.

Next, in step S105, the error rate ERROR 1 in the previous reception is compared with the error rate ERROR 2 in the current reception. If the error rate of the received signal is improved because the error rate ERROR 2 in the current reception is smaller than the error rate ERROR 1 in the previous reception, then it is determined that the received signal can be improved by controlling the threshold value of the electric field strength level at which the AGC operation is started error rate. Therefore, in order to keep the change of the threshold value of the electric field strength level for starting the AGC operation in the subsequent reception in the same direction as the change of the threshold value of the electric field strength level for starting the AGC operation in the previous reception, the pole of changing the control amount d is not changed. sex. Conversely, if the error rate of the received signal has deteriorated due to the error rate ERROR 2 in the current reception being greater than the error rate ERROR 1 in the previous reception, then it is determined that the error rate of the received signal has been reduced by controlling the initial electric mean value of the AGC operation. It got worse. Therefore, in step S106, in order that the electric field intensity level threshold value of starting AGC operation in subsequent reception can be changed along the direction opposite to the electric field intensity level threshold value of starting AGC operation in previous reception, the reverse change control amount d polarity.

Finally, in step S107, the error rate ERROR 2 in the current reception is stored in ERROR 1, ready to be used in subsequent reception, and the value obtained by adding the change control amount d to the set value START in the current reception is stored as The electric field strength level threshold for starting AGC operation in subsequent receptions. In addition, when receiving the power of the radio receiver, the receiving operation is still performed by repeating the above steps S103 to S107.

As described above, in the electric field strength level threshold setting method for starting AGC operation according to the first example, since the electric field strength level threshold for starting AGC operation can be determined by appropriately determining the electric field strength level for starting AGC operation to be set subsequently Therefore, setting of the threshold value of the electric field intensity level optimally starting the AGC operation can be achieved in an environment of a strong electric field IM or an environment in which the electric field changes strongly.

(second example)

Next, FIG. 4 shows a flowchart of an electric field intensity level threshold setting method (second example) for starting AGC operation in the radio receiver according to the first embodiment. In the electric field intensity level threshold setting method for starting an AGC operation according to the second example, as in the first example, the electric field intensity level threshold for starting an AGC operation in subsequent reception is based on the value received in the previous reception and the current reception. The error rate measurement result of the signal is set. In addition, the controlled direction of the electric field strength level threshold for starting AGC operation can be controlled by storing the electric field strength level threshold for starting AGC operation and combining the electric field strength level threshold for starting AGC operation in the previous reception with the starting AGC in the current reception The electric field strength level threshold for operation is more appropriately determined, and therefore, such a determination result can be effectively used in setting the electric field strength level threshold for starting AGC operation in subsequent reception. In this case, the change amount of the threshold value of the electric field strength level at which the AGC operation is started is set to a constant value.

Next, each variable (parameter stored in the memory 108) used in FIG. 4 will be described. As in the first example, ERROR 1, ERROR 2, and d are the error rate in the previous reception, the error rate in the current reception, and the change control amount, respectively. START 1 is the set value of the threshold value of the electric field strength level at which the AGC operation was started in the previous reception, and START 2 is the set value of the threshold value of the electric field strength level at which the AGC operation was started in the current reception.

First, when receiving power of the radio receiver for initial setting in step S201, parameters ERROR 1, ERROR 2, START 1, START 2, and d are set to predetermined initial values in step S202. These steps S201, S202 are the initial setting processing procedure in the setting operation. Steps S203 to S213 as described later are to set the electric field strength level threshold for starting the AGC operation by appropriately determining the change direction of the electric field strength level threshold for starting the AGC operation to be set subsequently, and after receiving has been performed a predetermined number of times The processing that takes place per reception or every few receptions.

In step S203, a radio signal is received by setting the electric field strength level threshold for starting AGC operation to START 2 . In step S204, the error rate measurement circuit 109 measures the error rate of the received signal, and then stores the measurement result in ERROR 2 as the error rate currently being received.

In step S205, the error rate ERROR 2 in the current reception is compared with the error rate ERROR 1 in the previous reception, to determine whether the error rate ERROR 2 in the current reception is less than the error rate ERROR 1 in the previous reception, thereby improving The error rate of the received signal. In steps S206, S209, in order to detect which direction the electric field strength level threshold value of starting AGC operation changes to to cause the change of error rate, the electric field strength level threshold value START 2 of starting AGC operation in current reception is compared with the previous reception Compared with the electric field strength level threshold START 1 to start AGC operation.

In step S205, if it is determined that the error rate of the received signal is improved, the process proceeds to step S206. In step S206, if the electric field strength level threshold START 2 for starting the AGC operation in the current reception is greater than the electric field strength level threshold START 1 for starting the AGC operation in the previous reception, then the process proceeds to step S207. Then, the sign of changing the control amount d is being set so that the electric field intensity level threshold value for starting AGC operation in subsequent reception can be increased to be larger than the electric field intensity level threshold value START 2 for starting AGC operation in current reception. Conversely, in step S206, if the electric field strength level threshold START 2 for starting the AGC operation in the current reception is smaller than the electric field strength level threshold START 1 for starting the AGC operation in the previous reception, then the process proceeds to step S208. Then, the negative setting changes the sign of the control amount so that the electric field strength level threshold for starting the AGC operation in the subsequent reception can be reduced to be smaller than the electric field strength level threshold START 2 for starting the AGC operation in the current reception.

On the contrary, in step S205, if it is determined that the error rate of the received signal has deteriorated, the process proceeds to step S209. In step S209, if the electric field strength level threshold START 2 for starting the AGC operation in the current reception is smaller than the electric field strength level threshold START 1 for starting the AGC operation in the previous reception, the process proceeds to step S210. Then, the sign of changing the control amount d is being set so that the electric field strength level threshold value for starting AGC operation in subsequent reception can be increased to be larger than the electric field strength level threshold value START 2 for starting AGC operation in current reception. Otherwise, in step S209, if the electric field strength level threshold START 2 of starting the AGC operation in the current reception is greater than the electric field strength level threshold START 1 of starting the AGC operation in the previous reception, then the process proceeds to step S211. Then, the negative setting changes the sign of the control amount so that the electric field strength level threshold for starting AGC operation in subsequent reception can be reduced to be smaller than the electric field strength level threshold START 2 for starting AGC operation in current reception.

Finally, in order to prepare for subsequent reception, in step S212, the electric field strength level threshold START 2 for starting the AGC operation in current reception is stored in START 1. In addition, in step S213, the error rate ERROR 2 in the current reception is stored in ERROR 1, and the value obtained by adding the change control amount d to the set value START 2 in the current reception is stored in START 2 as the subsequent reception The electric field strength level threshold for starting AGC operation in . In addition, when receiving the power of the radio receiver, the receiving operation is still performed by repeating the above steps S203 to S213.

As described above, in the electric field strength level threshold setting method for starting the AGC operation according to the second example, if the error rate of the received signal is improved, the electric field strength level threshold for starting the AGC operation can be along the same line as in the previous reception. The electric field strength level threshold for starting AGC operation increases/decreases in the same direction, and conversely, if the error rate of the received signal becomes worse, the electric field strength level threshold for starting AGC operation can be along the same direction as the start AGC in the previous reception. The electric field strength level threshold of operation increases/decreases in the opposite direction. Therefore, since the electric field strength level threshold value for starting AGC operation can be set by more appropriately determining the direction of change of the electric field strength level threshold value for starting AGC operation to be set subsequently, it is possible to set the electric field strength level threshold value in the environment of strong electric field IM or in which electric field occurs. Set a more appropriate electric field strength level threshold to start AGC operation under strongly changing environment.

(third example)

FIG. 5 is a flowchart showing an electric field intensity level threshold setting method (third example) for starting AGC operation in the radio receiver according to the first embodiment. In the electric field strength level threshold setting method for starting AGC operation according to the third example, in addition to the above-mentioned determination of the direction of change of the electric field strength level threshold for starting AGC operation as in the first example, the electric field strength for starting AGC operation The amount of change of the level threshold can also be changed according to the amount of error rate change, so that if the amount of change of the error rate is less than a predetermined value, the amount of change of the electric field strength level threshold for starting AGC operation remains on the original constant value, and if The change amount of the error rate is larger than the predetermined value, and the change amount of the threshold value of the electric field strength level at which the AGC operation is started is changed to the predetermined value.

Next, each variable (parameter stored in the memory 108) used in FIG. 5 will be described. As in the first example, ERROR 1, ERROR 2, START, and d are the error rate in the previous reception, the error rate in the current reception, the setting value and the change control amount of the electric field strength level threshold for starting AGC operation, respectively. In addition, REF 1 is a reference value of the error rate change amount of the received signal per control step size (change control amount d) of the threshold value of the electric field strength level at which the AGC operation is started. If the value obtained by dividing the absolute value of the difference between ERROR 1 and ERROR2 by a change amount control parameter n as described later exceeds REF 1, then such a change amount control parameter n is changed such that the AGC operation is started in the subsequent reception The amount by which the electric field strength level threshold is changed. In addition, n0 is a value set as the change amount control parameter n when the change amount of the error rate of the received signal exceeds REF 1 per control step size (change control amount d) of the threshold value of the electric field intensity level at which the AGC operation is started. And, ΔS is the change amount of the threshold value of the electric field intensity level at which the AGC operation is started, and a value n times the change control amount d is set as ΔS.

First, when receiving the power of the radio receiver for initial setting in step S301, in step S302, parameters ERROR 1, ERROR 2, START, d, ΔS, REF 1, n, and n0 are all set to predetermined initial values. These steps S301 and S302 are the initial setting processing procedure in the setting operation. Steps S303 to S311 as described later are to set the electric field strength level threshold value to start the AGC operation by properly determining the direction of change and determining the amount of change to be set subsequently, and the electric field strength level threshold value that has been received The processing is performed every reception or every few receptions after a predetermined number of receptions.

In step S303, a radio signal is received by setting an electric field strength level threshold for starting AGC operation to STRRT. In step S304, the error rate measurement circuit 109 measures the error rate of the received signal, and then stores the measurement result in ERROR 2 as the error rate currently being received.

Next, in step S305, the error rate ERROR 2 in the current reception is compared with the error rate ERROR 1 in the current reception. If the error rate ERROR 2 in the current reception is smaller than the error rate ERROR 1 in the previous reception, and thus the error rate of the received signal is improved, then it is determined that the error rate of the received signal can be determined by the electric field strength level at which the AGC operation is started Threshold control is improved. Therefore, to change the electric field strength level threshold for starting AGC operation in subsequent reception in the same direction as the electric field strength level threshold for starting AGC operation in previous reception, the polarity of change control amount d is not changed. Conversely, if the error rate ERROR 2 in the current reception is greater than the error rate ERROR 1 in the previous reception, and thus the error rate of the received signal becomes worse, then it is determined that the error rate of the received signal is determined by the electric field strength at which the AGC operation is started level threshold control goes bad. Then, the process proceeds to step S306. In step S306, the polarity of the control amount d is reversely changed so that the electric field strength level threshold for starting AGC operation in the subsequent reception can be along the same line as that of the previous reception for starting AGC operation. The electric field strength level changes in the opposite direction to the threshold.

Then, in step S307, the value obtained by dividing the absolute value of the difference between the error rate ERROR 1 in the previous reception and the error rate ERROR 2 in the current reception by the change amount control parameter n is compared with the reference value REF1. If the value obtained by dividing the absolute value of the difference between ERROR 1 and ERROR 2 by the amount of change control parameter n exceeds REF 1, the process proceeds to step S308, where n0 is set as the amount of change control parameter n. On the contrary, if the absolute value of the difference between ERROR 1 and ERROR 2 is divided by the value obtained by the change amount control parameter n is less than REF 1, then the process proceeds to step S309, and in step S309, "1" is set as the change amount control parameter n .

Next, in step S310, a value n times the change control amount d is set as the change amount ΔS of the threshold value of the electric field intensity level for starting the AGC operation. Finally, in order to prepare for subsequent reception, in step S311, the error rate ERROR 2 in the current reception is stored in ERROR 1, and the value obtained by adding the change amount ΔS to the set value START in the current reception is stored in START is used as the electric field strength level threshold for starting AGC operation in subsequent reception. In addition, when receiving the power of the radio receiver, the receiving operation is still performed by repeating the above steps S303 to S311.

As described above, in the electric field intensity level threshold setting method for starting AGC operation according to the third example, the operation start electric field value can be determined by appropriately determining the change direction of the electric field intensity level threshold value for starting AGC operation to be set subsequently. To set, the change amount of the threshold value of the electric field strength level at which the AGC operation starts can be changed according to the change amount of the error rate. Therefore, it is possible to set a more appropriate electric field intensity level threshold value for starting the AGC operation in an environment of a strong electric field IM or an environment in which an electric field is strongly changed.

(fourth example)

FIG. 6 is a flowchart showing an electric field intensity level threshold setting method (fourth example) for starting AGC operation in the radio receiver according to the first embodiment. In the electric field strength level threshold setting method for starting AGC operation according to the fourth example, before the above determination of the direction of change of the electric field strength level threshold for starting AGC operation as in the first example, when the error rate exceeds a predetermined value The threshold value of the electric field strength level at which the AGC operation is started is returned to a predetermined initial value. In this case, the change amount of the threshold value of the electric field intensity level at which the AGC operation is started is set to a constant value.

Next, each variable/(parameter stored in the memory 108) used in FIG. 6 will be described. As in the first example, ERROR 1, ERROR 2, START, and d are the error rate in the previous reception, the error rate in the current reception, the setting value and the change control amount of the electric field strength level threshold for starting AGC operation, respectively. In addition, REF 2 is a reference value compared with the error rate ERROR 2 currently being received. In addition, START 0 is a predetermined set value of the threshold value of the electric field intensity level at which the AGC operation is started. When the error rate ERROR 2 in the current reception exceeds the reference value REF 2, the electric field strength level threshold (START) for starting the AGC operation is set to a predetermined set value START 0.

First, when the power supply of the radio receiver is received for initial setting in step S401, the parameters ERROR 1, ERROR 2, START, d, REF 2, and START 0 are all set to predetermined initial values in step S402. These steps S401 and S402 are the initial setting processing procedure in the setting operation. Steps S403 to S409 as described later are to set the electric field strength level threshold for starting the AGC operation by appropriately determining the direction of change of the electric field strength level threshold for starting the AGC operation to be set subsequently, and after receiving has been performed a predetermined number of times The processing that takes place per reception or every few receptions.

In step S403, a radio signal is received by setting the threshold value of the electric field strength level to start the AGC operation to START. In step S404, the error rate measurement circuit 109 measures the error rate of the received signal, and then stores the measurement result in ERROR 2 as the error rate currently being received.

Next, in step S405, the error rate ERROR 2 currently being received is compared with the reference value REF 2. If the error rate ERROR 2 in the current reception exceeds the reference value REF 2, the process proceeds to step S406, and in step S406, START 0 is set as the electric field strength level threshold (START) of starting AGC operation in subsequent reception. Then, the process proceeds to step S410, and in step S410, the value of the error rate ERROR 2 in the current reception is stored in ERROR 1 to be used in subsequent reception. On the contrary, if the error rate ERROR 2 in the current reception does not exceed the reference value REF2, the process proceeds to step S407.

In step S407, the error rate ERROR 2 in the current reception is compared with the error rate ERROR 1 in the previous reception. If the error rate ERROR 2 in the current reception is smaller than the error rate ERROR 1 in the previous reception, and thus the error rate of the received signal is improved, then it is determined that the error rate of the received signal can pass the electric field strength level threshold for starting AGC operation Control is improved. Therefore, to change the electric field strength level threshold for starting AGC operation in subsequent reception in the same direction as the electric field strength level threshold for starting AGC operation in previous reception, the polarity of change control amount d is not changed. Conversely, if the error rate ERROR 2 in the current reception is greater than the error rate ERROR 1 in the previous reception, and thus the error rate of the received signal becomes worse, then it is determined that the error rate of the received signal is determined by the electric field strength at which the AGC operation is started level threshold control goes bad. Then, the process proceeds to step S408. In step S408, the polarity of the control amount d is reversely changed, so that the electric field strength level threshold value for starting the AGC operation in the subsequent reception can be along the same line as that of the starting AGC operation in the previous reception. The electric field strength level changes in the opposite direction to the threshold.

Finally, in step S409, in order to prepare for subsequent reception, the error rate ERROR 2 in the current reception is stored in ERROR 1, and the value obtained by adding the change control amount d to the set value START in the current reception is stored In START as the electric field strength level threshold for starting AGC operation in subsequent reception. In addition, when receiving the power of the radio receiver, the receiving operation is still performed by repeating the above steps S403 to S409.

As described above, in the electric field strength level threshold setting method for starting the AGC operation according to the fourth example, when setting the AGC operation starting point by appropriately determining the direction of change of the electric field strength level threshold value for starting the AGC operation to be set subsequently, Before the electric field strength level threshold, when the error rate exceeds a predetermined value, the electric field strength level threshold for starting the AGC operation returns to a predetermined initial value. Therefore, it is possible to set a more suitable electric field strength level threshold for starting the AGC operation under the environment of the strong electric field IM or the environment where the electric field strength changes strongly, and when the setting of the electric field strength level threshold for starting the AGC operation is obviously out of bounds, Appropriate precautions can be taken.

(fifth example)

FIG. 7 is a flowchart showing an electric field intensity level threshold setting method (fifth example) for starting AGC operation in the radio receiver according to the first embodiment. In the electric field strength level threshold setting method for starting AGC operation according to the fifth example, an available setting range of the electric field strength level threshold for starting AGC operation defined by a maximum value and a minimum value is set. Then, if the threshold value of the electric field strength level for starting the AGC operation is smaller than the minimum value of the available setting range, or greater than the maximum value thereof, then, when the error rate in current reception is lower than a predetermined value, the electric field strength level for starting the AGC operation is not changed. Flat threshold setting. Conversely, if the threshold value of the electric field strength level for starting the AGC operation falls within the available setting range, the direction of change of the threshold value of the electric field strength level for starting the AGC operation is determined as in the first example. In this case, the change amount of the threshold value of the electric field strength level at which the AGC operation is started is set to a constant value.

Next, each variable (parameter stored in the memory 108) used in FIG. 7 will be described. As in the first example, ERROR 1, ERROR 2, START, and d are the error rate in the previous reception, the error rate in the current reception, the setting value and the change control amount of the electric field strength level threshold for starting AGC operation, respectively. In addition, S_MIN and S_MAX are the minimum set value and the maximum set value of the threshold value of the electric field strength level for starting the AGC operation, respectively, and control the setting of the maximum value and the minimum value of the threshold value of the electric field strength level for starting the AGC operation from S_MIN to Move within the range of S_MAX. And, REF 3 is a reference value compared with the error rate ERROR 2 in current reception when the electric field intensity level threshold value for starting the AGC operation is set lower than the minimum set value S_MIN. When the threshold value of the electric field strength level for starting the AGC operation is set to be lower than the minimum set value S_MIN and the error rate ERROR 2 in the current reception is less than the reference value REF 3, the setting of the threshold value of the electric field strength level for starting the AGC operation is not changed. In addition, REF 4 is a reference value compared with the error rate ERROR 2 currently in reception when the electric field intensity level threshold value for starting the AGC operation is set higher than the maximum set value S_MAX. When the electric field strength level threshold for starting the AGC operation is set higher than the maximum set value S_MAX and the error rate ERROR 2 in current reception is less than the reference value REF 4, the setting of the electric field strength level threshold for starting the AGC operation is not changed.

First, when the power supply of the radio receiver is received for initial setting in step S501, the parameters ERROR 1, ERROR 2, START, d, REF 3, REF 4, S_MIX, and S_MAX are all set to predetermined initial values in step S502. These steps S501 and S502 are the initial setting processing procedure in the setting operation. Steps S503 to S514 as described later are to set the electric field strength level threshold for starting the AGC operation by appropriately determining the change direction of the electric field strength level threshold for starting the AGC operation to be set subsequently, and after receiving has been performed a predetermined number of times The processing that takes place per reception or every few receptions.

In step S503, a radio signal is received by setting the electric field strength level threshold value for starting AGC operation to START. In step S504, the error rate measurement circuit 109 measures the error rate of the received signal, and then stores the measurement result in ERROR 2 as the error rate currently being received.

Next, in step S505, it is determined whether the setting of the electric field strength level threshold (START) for starting the AGC operation in the current reception is smaller than the minimum setting value S_MIN. If the setting of the electric field strength level threshold value (START) to start the AGC operation exceeds the minimum set value S_MIN, the process proceeds to step S506. On the contrary, if the setting of the electric field strength level threshold value (START) to start the AGC operation is smaller than the minimum set value S_MIN, the process proceeds to step S507. In step S507, the error rate ERROR 2 in the current reception is compared with the reference value REF 3. If the error rate in current reception exceeds the reference value REF3, the process proceeds to step S508. Then, the sign of the change control amount is being set so that the threshold value of the electric field strength level to start the AGC operation in the subsequent reception is incremented by one step, and the process proceeds to step S513. Conversely, if the error rate ERROR 2 in the current reception is less than the reference value REF 3, the setting of the electric field strength level threshold for starting the AGC operation is not changed. Then, the processing procedure advances to step S514, and in step S514, the value of the error rate ERROR 2 in the current reception is stored in ERROR 1, and is ready for subsequent reception.

Conversely, if the setting of the electric field strength level threshold value (START) to start the AGC operation exceeds the minimum set value S_MIN, the process proceeds to step S506. In this case, in step S506, it is determined whether the setting of the electric field strength level threshold value (START) for starting the AGC operation in the current reception exceeds the maximum setting value S_MAX. If the setting of the electric field strength level threshold value (START) to start the AGC operation is smaller than the maximum setting value S_MAX, the process proceeds to step S511. Conversely, if the setting of the electric field strength level threshold value (START) for starting the AGC operation exceeds the maximum setting value S#MAX, the process proceeds to step S509. In step S509, the error rate ERROR 2 in the current reception is compared with the reference value REF 4. If the error rate ERROR 2 in the current reception exceeds the reference value REF 4, the process proceeds to step S510. Then, the negative setting changes the sign of the control amount d so that the electric field strength level threshold value for starting AGC operation in subsequent reception is decremented by one step, and the process proceeds to step S513. Also, if the error rate ERROR 2 in the current reception is smaller than the reference value REF 4, the setting of the electric field strength level threshold for starting the AGC operation is not changed, and the process proceeds to step S514. Then, the value of the error rate ERROR 2 in the current reception is stored in ERROR 1, ready for subsequent reception.

On the contrary, if the setting of the electric field strength level threshold value (START) to start the AGC operation is smaller than the maximum setting value S_MAX, the process proceeds to step S511. In step S511, the error rate ERROR 2 in the current reception is compared with the error rate ERROR 1 in the previous reception. If the error rate ERROR 2 in the current reception is smaller than the error rate ERROR 1 in the previous reception, and thus the error rate of the received signal is improved, then it is determined that the error rate of the received signal can pass the electric field strength level threshold for starting AGC operation Control is improved. Therefore, to change the electric field strength level threshold for starting AGC operation in subsequent reception in the same direction as the electric field strength level threshold for starting AGC operation in previous reception, the polarity of the change control amount is not changed. Conversely, if the error rate ERROR 2 in the current reception is greater than the error rate ERROR 1 in the previous reception, and thus the error rate of the received signal becomes worse, then it is determined that the error rate of the received signal is determined by the electric field strength at which the AGC operation is started level threshold control goes bad. Then, the process proceeds to step S512. In step S512, the polarity of the control quantity is reversed so that the electric field strength level threshold for starting the AGC operation in the subsequent reception can be along the same line as that of the starting AGC operation in the previous reception. The electric field strength level changes in the opposite direction to the threshold.

Finally, in step S513, in order to prepare for subsequent reception, the error rate ERROR 2 in the current reception is stored in ERROR 1, and the value obtained by adding the change control amount d to the set value START in the current reception is stored In START as the electric field strength level threshold for starting AGC operation in subsequent reception. In addition, when receiving the power of the radio receiver, the receiving operation is still performed by repeating the above steps S503 to S514.

As described above, in the electric field strength level threshold setting method for starting AGC operation according to the fifth example, an available setting range defined by the maximum and minimum values of the electric field strength level threshold for starting AGC operation is set. Then, if the electric field strength level threshold value for starting AGC operation is less than the minimum value of the available setting range, or greater than its maximum value, then when the error rate in current reception is lower than a predetermined value, the electric field strength level for starting AGC operation is not changed Threshold setting. Conversely, if the electric field strength level threshold for starting the AGC operation is within the available setting range, the electric field strength level threshold for starting the AGC operation is set by changing the direction suitable for determining the electric field strength level threshold for starting the AGC operation to be set subsequently . Therefore, it is possible to set an optimum electric field strength level threshold value for starting AGC operation under an environment of a strong electric field IM or an environment in which an electric field is strongly changed, and it is possible to prevent the setting value of the electric field strength level threshold value for starting AGC operation from being In the case of setting to the maximum value or the minimum value, there occurs a case where the set value of the electric field strength level threshold value for starting the AGC operation is changed unnecessarily when the error rate is sufficiently small.

As described above, according to the radio receiver and the radio receiving method of the first embodiment, since the electric field intensity level threshold for starting the AGC operation is set by the error rate measurement circuit 109 based on the measurement result of the error rate of the received signal, it is possible to The electric field strength level threshold for optimally starting AGC operation is set to be suitable for the radio environment in which the radio receiver is located, that is, the reception environment in which the signal is received, and can also be in an environment characterized by IM or electric field variation, for example, in a strong electric field In the environment of IM, or an environment in which the electric field changes strongly, the gain control of the gain control means is obtained to optimize the signal quality of the received signal. As a result, the communication quality in mobile radio communication can be considerably improved.

[Second embodiment]

Next, FIG. 8 is a block diagram showing the structure of a radio receiver according to a second embodiment of the present invention.

In FIG. 8, the radio receiver according to the second embodiment is constructed to include an antenna 201, a low noise signal amplifier (LNA) 202, a local oscillator circuit (Local) 203, a frequency converter circuit (Mix) 204, an electric field Intensity detector 205 , gain control circuit 206 , signal processor section 207 , memory 208 and error rate measurement circuit 209 .

The antenna 201 receives a signal transmitted from a base station (not shown in the figure). The low noise signal amplifier 202 amplifies a signal received through the antenna 201 . The frequency converter circuit 204 performs frequency conversion by multiplying the signal amplified by the low-noise signal amplifier 202 and the signal from the local oscillator circuit 203 .

The electric field intensity detector 205 changes the voltage of the output signal GC2 according to the intensity of the received signal whose frequency is converted to an intermediate frequency (IF) by the frequency converter circuit 204 . The gain control circuit 206 changes the gain control amount according to the output signal GC2 from the electric field intensity detector 205 and the control parameter (signal CN2 ) from the signal processor section 207 .

The memory 208 corresponds to a storage device. In this memory 208, the error rate measurement result in the previous reception, the setting value of the gain control amount in the previous reception, other parameters used in the process of setting the gain control amount in the subsequent reception, and Then receive the gain control amount etc. set by the above-mentioned process.

The signal processor section 207 corresponds to gain control amount setting means and second control means. This signal processor section 207 demodulates the received signal, and is set based on the error rate data of the received signal and the set value obtained in the AGC by comparing the data in the current reception with the data stored in the memory 208 in the previous reception. AGC gain control amount, and control the gain control circuit 206 by providing a control parameter (signal CN2). Furthermore, the signal processor section 207 updates the error rate measurement result stored in the memory 208 in the previous reception with the error rate measurement result in the current reception, and updates the error rate measurement result in the previous reception with the gain control amount set in the current reception. The set value of the gain control amount is updated, and the gain control amount set in the next reception is updated with the gain control amount set by the signal processor section 207 in the current reception.

As described above, the AGC gain control amount to be set in the current reception is determined by the processing performed by the signal processor section 207 in the previous reception, and stored in the memory 208 . The signal processor section 207 controls the setting of the gain control circuit 206 by outputting the control signal CN2 based on the stored gain control amount obtained by looking up the memory 208 .

Next, a specific structure for changing the setting of the gain control amount in the gain control circuit 206 based on the output signal GC1 from the electric field intensity detector 205 and the control signal CN2 from the signal processor section 207 will be described below with reference to FIG. 9 . FIG. 9 shows a specific structure of the gain control circuit 206 in the radio receiver according to the second embodiment. In FIG. 9 , the gain control circuit 206 is configured to include a current limiting resistor R1 , a capacitor C1 , a diode D1 and a control voltage conversion circuit 211 .

The capacitor C1 is used as a coupling capacitor, cuts off a DC (direct current) component of a received signal, and is used to adjust a gain control amount. In general, a PIN diode or a band switching diode is used as the diode D1, and has a characteristic that the impedance between the anode and the cathode of the diode D1 decreases with the current flowing through the diode D1.

Configure current limiting resistor R1 to prevent excessive current from flowing through diode D1. If the signal level of the output signal GC2 supplied from the electric field strength detector 205 exceeds a certain constant value, the control voltage conversion circuit 211 outputs the output voltage set by the control signal CN2 from the signal processor section 207 .

When an intermediate frequency (IF) signal whose level exceeds a predetermined value is input, the electric field strength detector 205 outputs a signal GC2 to the control voltage conversion circuit 211 to start the AGC operation. The output voltage of the gain control circuit 206 is switched by the control signal CN2 supplied from the signal processor section 207 . Since the current value flowing through the diode D1 is changed by converting the output voltage, the impedance between the anode and the cathode can be changed, and thus the gain control amount can be changed. In this way, in the gain control circuit 206 shown in FIG.

As a specific example of the structure for changing the setting of the gain control amount, in addition to the first specific structure shown in FIG. 9 above, the following specific structures can also be considered.

For example, as a second specific structure, a structure may be considered in which an output voltage conversion circuit whose output voltage can be converted is provided to the low noise signal amplifier (LNA) 202 . Then, according to the control signal responsive to the error rate measurement result from the signal processor section 207, the output voltage of the output voltage conversion circuit in the low noise signal amplifier 202 is switched/set to change the gain control amount.

Furthermore, as a third specific structure, a structure may be considered in which a current source having a current conversion function is provided to the low noise signal amplifier (LNA) 202, and then, based on the The control signal converts/sets the current value of the current source with current conversion function in the low noise signal amplifier 202 to change the gain control amount.

The error rate measurement circuit 209 corresponds to error rate measurement means. For example, this error rate measurement circuit 209 is composed of a BCH code correction circuit, and calculates the error rate of the signal based on the number of error corrections and the number of uncorrected errors of the demodulated signal. The measurement principle of the error rate measurement circuit 209 is similar to that explained in the first embodiment.

Next, the radio receiving method in the radio receiver having the above structure according to the second embodiment will be described in detail below in order of the first example, the second example, the third example, the fourth example and the fifth example with reference to the accompanying drawings. (An example of an AGC gain control amount setting method using a measurement result of a received signal obtained by the error rate measurement circuit 109). In the following description, it is assumed that if the set value of the gain control amount is a small value, the gain control amount is also set to a small value, and if the set value of the gain control amount is a large value, then Also set the gain control amount to a large value.

(first example)

Fig. 10 shows a flowchart of the AGC gain control amount setting method (first example) in the radio receiver according to the second embodiment. In the gain control amount setting method of the first example, if the error rate in the current reception is smaller than the error rate in the previous reception, then the change direction of the gain control amount in the subsequent reception continues to be the same as that in the previous reception. The change direction of the gain control amount is the same direction, because the error rate can be improved in this way, and if the error rate in the current reception is greater than the error rate in the previous reception, then, because the error rate has become worse, so , switching the change direction of the gain control amount in the subsequent reception to the direction opposite to the change direction of the gain control amount in the previous reception. In this case, the change amount of the gain control amount is set to a constant value.

Next, each variable (parameter stored in the memory 208) used in FIG. 10 will be described. ERROR 1 is the error rate measurement result of the received signal in the previous reception, and is set to an initial value as described later when initially setting up the radio receiver. ERROR 2 is the error rate measurement result of the received signal in the current reception. RED is a set value of the AGC gain control amount, and g is a change control amount for changing the AGC gain control amount.

First, when the power of the radio receiver is received for initial setting in step S601, parameters ERROR 1, ERROR 2, RED, and g are set to predetermined initial values in step S602. These steps S601 and S602 are the initial setting processing procedure in the setting operation. Steps S603-S607 as described later is a process of setting the gain control amount by appropriately determining the change direction of the gain control amount to be set subsequently, and performing each reception or every several receptions after the reception has been performed a predetermined number of times .

In step S603, a radio signal is received by setting a gain control amount to RED. In step S604, the error rate measurement circuit 209 measures the error rate of the received signal, and then stores the measurement result in ERROR 2 as the error rate currently being received.

Next, in step S605, the error rate ERROR 1 in the previous reception is compared with the error rate ERROR 2 in the current reception. If the error rate of the received signal is improved because the error rate ERROR 2 in the current reception is smaller than the error rate ERROR 1 in the previous reception, then it is determined that the error rate of the received signal can be improved by controlling the AGC gain control amount. Therefore, in order to keep the change of the AGC gain control amount in the subsequent reception in the same direction as the change of the AGC gain control amount in the previous reception, the polarity of the change control amount g is not changed. Conversely, if the error rate of the received signal has deteriorated due to the error rate ERROR 2 in the current reception being greater than the error rate ERROR 1 in the previous reception, then it is determined that the error rate of the received signal has deteriorated by controlling the AGC gain control amount up. Therefore, the processing proceeds to step S606. In order to change the AGC gain control amount in the subsequent reception in the opposite direction to the AGC gain control amount in the previous reception, the polarity of the change control amount g is reversed.

Finally, in step S607, the error rate ERROR 2 in the current reception is stored in ERROR 1, ready to be used in subsequent reception, and the value obtained by adding the change control amount g to the set value RED in the current reception is stored as The amount of AGC gain control in subsequent receptions. In addition, when receiving the power of the radio receiver, the receiving operation is still performed by repeating the above steps S603 to S607.

As described above, in the gain control amount setting method according to the first example, since the gain control amount can be set by appropriately determining the change direction of the gain control amount to be set subsequently. Therefore, setting of the optimum gain control amount can be realized in an environment of a strong electric field IM or an environment in which an electric field is strongly changed.

(second example)

FIG. 11 is a flowchart showing an AGC gain control amount setting method (second example) in the radio receiver according to the second embodiment. In the gain control amount setting method according to the second example, as in the first example, the AGC gain control amount in subsequent reception is set based on the error rate measurement results of received signals in previous reception and current reception. In addition, the controlled direction of the AGC gain control amount can be more properly determined by storing the AGC gain control amount and comparing the AGC gain control amount in the previous reception with the AGC gain control amount in the current reception, so such determination The result can be effectively used in setting the AGC gain control amount in subsequent receptions. In this case, the change amount of the gain control amount is set to a constant value.

Next, each variable (parameter stored in the memory 208) used in FIG. 11 will be described. As in the first example, ERROR 1, ERROR 2, and g are the error rate in the previous reception, the error rate in the current reception, and the change control amount, respectively. RED 1 is the set value of the AGC gain control amount in the previous reception, and RED 2 is the set value of the AGC gain control amount in the current reception.

First, when the power supply of the radio receiver is received for initial setting in step S701, parameters ERROR 1, ERROR 2, RED 1, RED 2, and g are set to predetermined initial values in step S702. These steps S701, S702 are the initial setting processing procedure in the setting operation. Steps S703 to S713 as described later are processing procedures for setting the gain control amount by appropriately determining the change direction of the gain control amount to be set subsequently, and performing each reception or every several receptions after the reception has been performed a predetermined number of times .

In step S703, a radio signal is received by setting a gain control amount for RED 2. In step S704, the error rate measurement circuit 209 measures the error rate of the received signal, and then stores the measurement result in ERROR 2 as the error rate currently being received.

In step S705, the error rate ERROR 2 in the current reception is compared with the error rate ERROR 1 in the previous reception to determine whether the error rate ERROR 2 in the current reception is less than the error rate ERROR 1 in the previous reception, thereby improving The error rate of the received signal. In steps S706 and S709, in order to detect which direction the AGC gain control amount is changed to cause a change in the error rate, the AGC gain control amount RED 2 in the current reception is compared with the AGC gain control amount RED 1 in the previous reception.

In step S705, if it is determined that the error rate of the received signal is improved, the process proceeds to step S706. In step S706, if the gain control amount RED2 in the current reception is larger than the gain control amount RED1 in the previous reception, then the process proceeds to step S707. Then, the sign of changing the control amount g is being set so that the AGC gain control amount in the subsequent reception can be increased to be larger than the gain control amount RED2 in the current reception. On the contrary, in step S706, if the gain control amount RED2 in the current reception is smaller than the gain control amount RED1 in the previous reception, the process proceeds to step S708. Then, the negative setting changes the sign of the control amount g, so that the AGC gain control amount in subsequent reception can be reduced to be smaller than the gain control amount RED2 in the current reception.

On the contrary, in step S705, if it is determined that the error rate of the received signal has deteriorated, the process proceeds to step S709. In step S709, if the gain control amount RED2 in the current reception is smaller than the gain control amount RED1 in the previous reception, the process proceeds to step S710. Then, the sign of changing the control amount g is being set so that the AGC gain control amount in the subsequent reception can be increased to be larger than the gain control amount RED2 in the current reception. On the contrary, in step S709, if the gain control amount RED2 in the current reception is greater than the gain control amount RED1 in the previous reception, then the processing proceeds to step S711. Then, the negative setting changes the sign of the control amount so that the AGC gain control amount in subsequent reception can be reduced to be smaller than the gain control amount RED2 in current reception.

Finally, in order to prepare for subsequent reception, in step S712, the gain control amount RED 2 currently being received is stored in RED 1 . In addition, in step S713, the error rate ERROR2 in the current reception is stored in ERROR 1, and the value obtained by adding the change control amount g to the set value RED 2 in the current reception is stored in RED 2 as the value obtained in subsequent reception. The amount of AGC gain control. In addition, when receiving the power of the radio receiver, the receiving operation is still performed by repeating the above steps S703 to S713.

As described above, in the gain control amount setting method according to the second example, if the error rate of the received signal is improved, the gain control amount can be increased/decreased in the same direction as the gain control amount in the previous reception, Conversely, if the error rate of the received signal has deteriorated, the gain control amount can be increased/decreased in the direction opposite to the gain control amount in the previous reception. Therefore, since the gain control amount can be set by more appropriately determining the change direction of the gain control amount to be set subsequently, it is possible to set a more appropriate gain control amount in an environment of a strong electric field IM or an environment in which an electric field is strongly changed .

(third example)

12 is a flowchart showing an AGC gain control amount setting method (third example) in the radio receiver according to the second embodiment. In the gain control amount setting method according to the third example, in addition to the above determination of the change direction of the gain control amount as in the first example, the change amount of the gain control amount may also be changed according to the error rate change amount so that if If the amount of error rate change is smaller than the predetermined value, the change amount of the gain control amount is maintained at the original constant value, and if the error rate change amount is greater than the predetermined value, the change amount of the gain control amount is changed to a predetermined value.

Next, each variable (parameter stored in the memory 208) used in FIG. 12 will be described. As in the first example, ERROR 1, ERROR 2, RED, and g are the error rate in the previous reception, the error rate in the current reception, the setting value of the gain control amount, and the change control amount, respectively. In addition, REF 5 is a reference value of the error rate change amount of the received signal per control step size (change control amount g) of the AGC gain control amount. If the absolute value of the difference between ERROR 1 and ERROR 2 divided by the change amount control parameter m as described later exceeds REF 5, then such change amount control parameter m is changed, that is, the AGC gain in subsequent reception The amount of change in the control volume. In addition, mo is the value that is set as the change amount control parameter m when the change amount of the error rate of the received signal exceeds REF 5 by the control step size (change control amount g) of each AGC gain control amount. And, ΔR is the change amount of the AGC gain control amount, and a value m times the change control amount g is set as ΔR.

First, when the power supply of the radio receiver is received for initial setting in step S801, the parameters ERROR 1, ERROR 2, RED, g, ΔR, REF 5, m, and mo are all set to predetermined initial values in step S802. These steps S801 and S802 are the initial setting processing procedure in the setting operation. Steps S803 to S811 as described later are to set the gain control amount by appropriately determining the change direction of the gain control amount to be set subsequently and determining the change amount, and each reception or every several receptions after the reception has been performed a predetermined number of times processing performed.

In step S803, a radio signal is received by setting a gain control amount to RED. In step S804, the error rate measurement circuit 209 measures the error rate of the received signal, and then stores the measurement result in ERROR 2 as the error rate currently being received.

Next, in step S805, the error rate ERROR 2 in the current reception is compared with the error rate ERROR 1 in the current reception. If the error rate ERROR 2 in the current reception is smaller than the error rate ERROR 1 in the previous reception, and thus the error rate of the received signal is improved, then it is determined that the error rate of the received signal can be improved by the AGC gain control amount control. Therefore, in order to change the AGC gain control amount in subsequent reception in the same direction as the AGC gain control amount in previous reception, the polarity of changing the control amount g is not changed. Conversely, if the error rate ERROR 2 in the current reception is greater than the error rate ERROR 1 in the previous reception, and thus the error rate of the received signal becomes worse, then it is determined that the error rate of the received signal is changed by the AGC gain control amount control bad. Then, the process proceeds to step S806, where the polarity of the change control amount g is inverted so that the AGC gain control amount in the subsequent reception can be changed in the direction opposite to the AGC gain control amount in the previous reception .

Then, in step S807, the value obtained by dividing the absolute value of the difference between the error rate ERROR 1 in the previous reception and the error rate ERROR 2 in the current reception by the change amount control parameter m is compared with the reference value REF5. If the value obtained by dividing the absolute value of the difference between ERROR 1 and ERROR 2 by the change amount control parameter m exceeds REF 5, the process proceeds to step S808 where mo is set as the change amount control parameter m. Conversely, if the absolute value of the difference between ERROR 1 and ERROR 2 divided by the change amount control parameter m is less than REF 5, the process proceeds to step S809, where "1" is set as the change amount control parameter m .

Next, in step S810, a value m times the change control amount g is set as the change amount ΔR of the AGC gain control amount. Finally, in order to prepare for subsequent reception, in step S811, the error rate ERROR 1 currently being received is stored in ERROR 1, and the value obtained by adding the change amount ΔR to the set value RED currently being received is stored in RED is used as the AGC gain control amount in subsequent reception. In addition, when receiving the power of the radio receiver, the receiving operation is still performed by repeating the above steps S803 to S811.

As described above, in the gain control amount setting method according to the third example, the gain control amount can be set by appropriately determining the change direction of the gain control amount to be set subsequently, and the change amount of the gain control amount can be set according to the error rate change amount Make changes. Therefore, it is possible to set a more appropriate gain control amount in an environment of a strong electric field IM or an environment in which an electric field is strongly changed.

(fourth example)

FIG. 13 is a flowchart showing an AGC gain control amount setting method (fourth example) in the radio receiver according to the second embodiment. In the gain control amount setting method according to the fourth example, the AGC gain control amount is returned to a predetermined initial value when the error rate exceeds a predetermined value before the above determination of the changing direction of the gain control amount as in the first example. In this case, the change amount of the gain control amount is set to a constant value.

Next, each variable/(parameter stored in the memory 208) used in FIG. 13 will be described. As in the first example, ERROR 1, ERROR 2, RED, and g are the error rate in the previous reception, the error rate in the current reception, the setting value of the gain control amount, and the change control amount, respectively. In addition, REF 6 is a reference value compared with the error rate ERROR 2 currently being received. In addition, RED 0 is a predetermined setting value of the AGC gain control amount. When the error rate ERROR 2 in the current reception exceeds the reference value REF 6, the AGC gain control amount (RED) is set to a predetermined setting value RED 0.

First, when receiving power of the radio receiver for initial setting in step S901, in step S902, parameters ERROR 1, ERROR 2, RED, g, REF 6, and RED 0 are all set to predetermined initial values. These steps S901 and S902 are the initial setting processing procedure in the setting operation. Steps S903 to S909 as described later are processing procedures for setting the gain control amount by appropriately determining the change direction of the gain control amount to be set subsequently, and performing each reception or every several receptions after the reception has been performed a predetermined number of times .

In step S903, a radio signal is received by setting a gain control amount to RED. In step S904, the error rate measurement circuit 209 measures the error rate of the received signal, and then stores the measurement result in ERROR 2 as the error rate currently being received.

Next, in step S905, the error rate ERROR 2 in current reception is compared with the reference value REF 6. If the error rate ERROR 2 in the current reception exceeds the reference value REF 6, then the processing procedure advances to step S906, and in step S906, RED 0 is set as the AGC gain control amount (RED) in subsequent reception. Then, the process proceeds to step S910, and in step S910, the value of the error rate ERROR 2 in the current reception is stored in ERROR 1 to prepare for subsequent reception. On the contrary, if the error rate ERROR 2 in the current reception does not exceed the reference value REF 6, the process proceeds to step S907.

In step S907, the error rate ERROR 2 in the current reception is compared with the error rate ERROR 1 in the previous reception. If the error rate ERROR 2 in the current reception is smaller than the error rate ERROR 1 in the previous reception, and thus the error rate of the received signal is improved, then it is determined that the error rate of the received signal can be improved by the AGC gain control amount control. Therefore, in order to change the AGC gain control amount in subsequent reception in the same direction as the AGC gain control amount in previous reception, the polarity of changing the control amount g is not changed. Conversely, if the error rate ERROR 2 in the current reception is greater than the error rate ERROR 1 in the previous reception, and thus the error rate of the received signal becomes worse, then it is determined that the error rate of the received signal is changed by the AGC gain control amount control bad. Then, the process proceeds to step S908, where the polarity of the control amount g is reversed so that the AGC gain control amount in the subsequent reception can be changed in the direction opposite to the AGC gain control amount in the previous reception .

Finally, in step S909, in order to prepare for subsequent reception, the error rate ERROR 2 in the current reception is stored in ERROR 1, and the value obtained by adding the change control amount g to the set value RED in the current reception is stored In RED as AGC gain control amount in subsequent reception. In addition, when receiving the power of the radio receiver, the receiving operation is still performed by repeating the above steps S903 to S910.

As described above, in the gain control amount setting method according to the fourth example, before setting the gain control amount by appropriately determining the change direction of the gain control amount to be set subsequently, when the error rate exceeds a predetermined value, the AGC gain control return to the predetermined initial value. Therefore, it is possible to set a more appropriate gain control amount in an environment of a strong electric field IM or an environment in which the electric field intensity changes strongly, and appropriate precautionary measures can be taken when the setting of the gain control amount is obviously out of bounds.

(fifth case)

Fig. 14 shows a flowchart of an AGC gain control amount setting method (fifth example) in the radio receiver according to the second embodiment. In the gain control amount setting method according to the fifth example, an available setting range of the gain control amount defined by a maximum value and a minimum value is set. Then, if the gain control amount is smaller than the minimum value of the available setting range, or larger than the maximum value, then, when the error rate in current reception is lower than a predetermined value, the setting of the gain control amount is not changed. Conversely, if the gain control amount falls within the available setting range, the direction of change of the gain control amount is determined as in the first example. In this case, the change amount of the gain control amount is set to a constant value.

Next, each variable (parameter stored in the memory 208) used in FIG. 14 will be described. As in the first example, ERROR 1, ERROR 2, RED, and g are the error rate in the previous reception, the error rate in the current reception, the setting value of the gain control amount, and the change control amount, respectively. In addition, RED_MIN and RED_MAX are the minimum set value and the maximum set value of the gain control amount, respectively, and control the setting of the maximum value and the minimum value of the AGC gain control amount to move within the range from RED_MIN to RED_MAX. And, REF 7 is a reference value compared with the error rate ERROR 2 in current reception when the AGC gain control amount is set lower than the minimum set value RED_MIN. When the AGC gain control amount is set lower than the minimum set value RED_MIN and the error rate ERROR 2 in current reception is less than the reference value REF 7, the setting of the gain control amount is not changed. In addition, REF 8 is a reference value compared with the error rate ERROR 2 currently in reception when the AGC gain control amount is set higher than the maximum set value RED_MAX. When the AGC gain control amount is set higher than the maximum set value RED_MAX and the error rate ERROR 2 in the current reception is less than the reference value REF 8, the setting of the gain control amount is not changed.

First, when the power supply of the radio receiver is received for initial setting in step S1001, the parameters ERROR 1, ERROR 2, RED, g, REF 7, REF 8, RED_MIN, and RED_MAX are all set to predetermined initial values in step S1002. These steps S1001 and S1002 are the initial setting processing procedure in the setting operation. Steps S1003 to S1014 as described later are processing procedures for setting the gain control amount by appropriately determining the change direction of the gain control amount to be set subsequently, and performing each reception or every several receptions after the reception has been performed a predetermined number of times .

In step S1003, a radio signal is received by setting a gain control amount to RED. In step S1004, the error rate measurement circuit 209 measures the error rate of the received signal, and then stores the measurement result in ERROR 2 as the error rate currently being received.

Next, in step S1005, it is determined whether the setting of the AGC gain control amount (RED) is smaller than the minimum setting value RED_MIN in the current reception. If the setting of the gain control amount (RED) exceeds the minimum set value RED_MIN, the process proceeds to step S1006. On the contrary, if the setting of the gain control amount (RED) is smaller than the minimum set value RED_MIN, the process proceeds to step S1007. In step S1007, the error rate ERROR 2 currently being received is compared with the reference value REF 7. If the error rate ERROR 2 in the current reception exceeds the reference value REF 7, the process proceeds to step S1008. Then, the sign of the change control amount g is being set so that the AGC gain control amount in subsequent reception is incremented by one step, and the process proceeds to step S1013. On the contrary, if the error rate ERROR 2 in the current reception is less than the reference value REF 7, the setting of the gain control amount will not be changed. Then, the processing procedure advances to step S1014, and in step S1014, the value of the error rate ERROR 2 in the current reception is stored in ERROR 1, and is prepared for subsequent reception.

On the contrary, if the setting of the gain control amount (RED) exceeds the minimum set value RED_MIN, the process proceeds to step S1006. In this case, in step S1006, it is determined whether the setting of the AGC gain control amount (RED) in current reception exceeds the maximum set value RED_MAX. If the setting of the AGC gain control amount (RED) is smaller than the maximum setting value RED_MAX, the process proceeds to step S1011. Conversely, if the setting of the AGC gain control amount (RED) exceeds the maximum set value RED_MAX, the process proceeds to step S1009. In step S1009, the error rate ERROR 2 in current reception is compared with the reference value REF 8. If the error rate ERROR 2 in current reception exceeds the reference value REF 8, the process proceeds to step S1010. Then, the sign of the change control amount g is negatively set so that the AGC gain control amount in subsequent reception is decremented by one step, and the process proceeds to step S1013. Also, if the error rate ERROR 2 in the current reception is smaller than the reference value REF 8, the setting of the gain control amount is not changed, and the process proceeds to step S1014. Then, the value of the error rate ERROR 2 in the current reception is stored in ERROR 1, ready for subsequent reception.

Conversely, if the setting of the AGC gain control amount (RED) is smaller than the maximum setting value RED_MAX, the process proceeds to step S1011. In step S1011, the error rate ERROR 2 in the current reception is compared with the error rate ERROR 1 in the previous reception. If the error rate ERROR 2 in the current reception is smaller than the error rate ERROR 1 in the previous reception, and thus the error rate of the received signal is improved, it is determined that the error rate of the received signal can be improved by the AGC gain control amount control. Therefore, in order to change the AGC gain control amount in the subsequent reception in the same direction as the AGC gain control amount in the previous reception, the polarity of changing the control amount g is not changed. Conversely, if the error rate ERROR 2 in the current reception is greater than the error rate ERROR 1 in the previous reception, and thus the error rate of the received signal becomes worse, then it is determined that the error rate of the received signal is changed by the AGC gain control amount control bad. Then, the process proceeds to step S1012, where the polarity of the control amount g is reversed so that the AGC gain control amount in the subsequent reception can be changed in the direction opposite to the AGC gain control amount in the previous reception .

Finally, in step S1013, in order to prepare for subsequent reception, store the error rate ERROR 2 in the current reception in ERROR 1, and store the value obtained by adding the change control amount g to the set value RED in the current reception In RED as AGC gain control amount in subsequent reception. In addition, when receiving the power of the radio receiver, the receiving operation is still performed by repeating the above steps S1003 to S1014.

As described above, in the gain control amount setting method according to the fifth example, an available setting range defined by the maximum and minimum values of the gain control amount is set. Then, if the gain control amount is smaller than the minimum value of the available setting range, or larger than its maximum value, when the error rate in current reception is lower than a predetermined value, the setting of the gain control amount is not changed. On the contrary, if the gain control amount is within the available setting range, the gain control amount is set by changing the direction suitable for determining the gain control amount to be set subsequently. Therefore, it is possible to set an optimum gain control amount in an environment of a strong electric field IM or an environment in which an electric field is strongly changed, and it is possible to prevent the A case occurs where the error rate is sufficiently small to change the set value of the gain control amount unnecessarily.

As described above, according to the radio receiver and the radio receiving method of the first embodiment, since the AGC gain control amount is set based on the measurement result of the error rate of the received signal by the error rate measurement circuit 209, the optimum AGC gain can be set The amount is controlled to suit the radio environment in which the radio receiver is placed, that is, the reception environment in which the signal is received, and may also be in an environment characterized by IM or electric field variation, for example, in an environment of strong electric field IM, or in which the electric field changes strongly Under the environment, the gain control of the gain control device is obtained to optimize the signal quality of the received signal. As a result, the communication quality in mobile radio communication can be considerably improved.

[Third embodiment]

Fig. 15 shows the structure of a radio receiver according to a third embodiment of the present invention.

In FIG. 15, the radio receiver according to the third embodiment is constructed to include an antenna 301, a low noise signal amplifier (LNA) 302, a local oscillator circuit (Local) 303, a frequency converter circuit (Mix) 304, an electric field Intensity detector 305 , gain control circuit 306 , signal processor section 307 and memory 308 .

The antenna 301 receives a signal transmitted from a base station (not shown in the figure). The low noise signal amplifier 302 amplifies a signal received through the antenna 301 . The frequency converter circuit 304 performs frequency conversion by multiplying the signal amplified by the low-noise signal amplifier 302 and the signal from the local oscillator circuit 303 .

When the electric field strength of the signal according to the control parameter (signal CN3) reaches the electric field strength level threshold for starting the AGC operation, the electric field strength detector 305 changes according to the strength of the received signal whose frequency is converted into an intermediate frequency (IF) by the frequency converter circuit 304 The voltage of the output signal GC3. The gain control circuit 306 changes the gain control amount in response to the output signal GC3 from the electric field strength detector 305 . In the memory 308, an electric field intensity level threshold to start the AGC operation to be set under various signal conditions, etc. are stored.

The signal processor section 307 corresponds to electric field intensity level threshold setting means for starting AGC operation. This signal processor section 307 demodulates the reception signal, and sets/changes the start of the AGC circuit by outputting the control signal CN3 to the electric field strength detector 305 according to the transmission condition such as the transmission data speed of the transmission signal interpreted according to the signal format. Electric field strength level threshold for AGC operation.

Next, a specific example of the radio reception method in the radio receiver having the above structure according to the third embodiment will be described in detail below with reference to FIG. 16 . FIG. 16 is a diagram showing that in a radio receiver receiving a signal having a signal format that is simultaneously transmitted while changing a signal condition such as a transmission data speed into two types or more, start AGC is separately set according to a signal transmission state Flowchart of a method of operating an electric field strength level threshold.

According to the radio reception method of the third embodiment, when transmitting a signal having a signal format that can be transmitted while changing the transmission condition to two types or more types, the transmission condition according to the signal is set by the signal processor section 307 The electric field strength level threshold for starting the AGC operation to start the gain control operation, and then the gain control operation is started when the electric field strength detected by the electric field strength detector 305 reaches the electric field strength level threshold for starting the AGC operation. Since the timing at which the signal condition such as the transmission data speed of the transmission signal is switched is always the same, if the signal received by the signal processor section 307 can be interpreted, it is possible by outputting the control signal CN3 to the electric field The intensity detector 305 changes the setting of the electric field intensity detector 305 and changes the electric field intensity level threshold value of the AGC circuit to start the AGC operation in synchronization with the signal condition transition timing.

Here, the following description is made on the assumption that the signal format can be transmitted while changing the transmission condition of the transmission data rate into two types of conditions. In this case, the first signal condition is a transmission signal in a signal format that changes the transmission condition such as the transmission data speed etc. The signal condition before the condition changed. The second signal condition is a signal condition after a change in transmission conditions such as transmission data speed or the like. In addition, as a specific example, in the signal format of the FLEX system pager, the signals in the first synchronous section in which the signals are transmitted at 1600 [bps], that is, the signals "BS1", "A", "B", "invA " and "F1", are set as the first signal condition, and the signal after the second synchronization section in which the signal is transmitted at 6400[bps], 3200[bps] or 1600[bps] is set as the second signal condition.

Next, each variable (parameter stored in the memory 308) used in FIG. 16 will be described. START-1 and START-2 are the setting values of the electric field strength level thresholds for starting the AGC operation which satisfy the first signal condition and the second signal condition respectively.

First, when receiving the power of the radio receiver for initial setting in step S1101, in step S1102, the electric field strength level threshold for starting AGC operation is set to the set value START-1 under the first signal condition. Then, in step S1103, the radio signal under the first signal condition is received.

Next, in step S1104, the control output CN3 of switching the electric field strength level threshold value for starting the AGC operation is output from the signal processor section 307 to the electric field strength according to the signal format when the signal condition is shifted from the first signal condition to the second signal condition. detector 305 . Then, in step S1105, according to the control signal CN3, the electric field strength level threshold for starting AGC operation is converted into the set value START_2 under the second signal condition, and then set to this value. Next, in step S1106, a radio signal under a second signal condition is received.

In the case where the radio receiver corresponds to a radio receiver performing a discontinuous receiving operation, in step S1106, the receiving operation is completed. If the receiving operation is performed again, the processing from steps S1102 to S1106 is repeated. On the other hand, in the case where the radio receiver corresponds to a radio receiver performing a continuous receiving operation, the process proceeds to step S1107, at step S1107, the A control signal CN3 for switching the threshold value of the electric field strength level at which the AGC operation starts is output from the signal processor section 307 to the electric field strength detector 305 . Then, the processing returns to step S1102. The receiving operation is continued by repeating the processing from steps S1102 to S1106.

As described above, according to the radio reception method of the third embodiment, when a signal having a signal format transmitted while changing transmission conditions such as transmission data speed into two types or more types is received, the control signal CN3 is output from the signal processor section 307 to the field strength detector 305 at signal condition transition timing to change the setting of the field strength detector 305 and thus change the field strength level threshold of the AGC circuit to start AGC operation. Therefore, the optimum gain control of the gain control means can be achieved to suit the signal transmission conditions, with the result that the communication quality under mobile radio communication can be considerably improved.

[Fourth embodiment]

Fig. 17 shows the structure of a radio receiver according to a fourth embodiment of the present invention.

In FIG. 17, a radio receiver according to the fourth embodiment is configured to include an antenna 401, a low noise signal amplifier (LNA) 402, a local oscillator circuit (Local) 403, a frequency converter circuit (Mix) 404, an electric field Intensity detector 405 , gain control circuit 406 , signal processor section 407 and memory 308 .

The antenna 401 receives a signal transmitted from a base station (not shown in the figure). The low noise signal amplifier 402 amplifies a signal received through the antenna 401 . The frequency converter circuit 404 performs frequency conversion by multiplying the signal amplified by the low-noise signal amplifier 402 and the signal from the local oscillator circuit 403 .

The electric field strength detector 405 changes the voltage of the output signal GC4 according to the strength of the received signal whose frequency is converted to an intermediate frequency (IF) by the frequency converter circuit 404 . The gain control circuit 406 changes the gain control amount in response to the output signal GC4 from the electric field intensity detector 405 and the control parameter (signal CN4 ) from the signal processor section 407 . In the memory 408, an electric field strength level threshold to start the AGC operation to be set under various signal conditions, etc. are stored.

The signal processor section 407 corresponds to gain control amount setting means and second control means. This signal processor section 407 demodulates the received signal, and sets/changes the gain control of the AGC circuit by outputting the control signal CN4 to the gain control circuit 406 according to the transmission condition such as the transmission data rate of the transmission signal interpreted in accordance with the signal format. quantity.

Next, a specific example of the radio receiving method in the radio receiver having the above structure according to the fourth embodiment will be described in detail below with reference to FIG. 18 . FIG. 18 is a graph showing that in a radio receiver receiving a signal having a signal format transmitted simultaneously while changing a signal condition such as a transmission data speed into two types or more, the AGC gain is separately set according to the signal transmission state Flowchart of the method of controlling volume.

According to the radio receiving method of the fourth embodiment, when transmitting a signal having a signal format that can be transmitted while changing the transmission condition into two types or more types, the transmission condition according to the signal is set by the signal processor section 407 The amount of gain control at which to start the gain control operation. Since the timing at which the signal condition such as the transmission data rate of the transmission signal is switched is always the same, if the signal received by the signal processor section 407 can be interpreted, it is possible to obtain the signal by outputting the control signal CN4 to the gain The control circuit 406 changes the setting of the gain control circuit 406 and changes the gain control amount of the AGC circuit in synchronization with the signal condition transition timing.

Here, the following description is made on the assumption that the signal format can be transmitted while changing the transmission condition of the transmission data rate into two types of conditions. In this case, the first signal condition and the second signal condition are similar to the third embodiment. Next, each variable (parameter stored in the memory 408) used in FIG. 18 will be described. RED-1 and RED-2 are the setting values of the AGC gain control amount set to satisfy the first signal condition and the second signal condition respectively.

First, when receiving the power of the radio receiver for initial setting at step S1201, at step S1202, the gain control amount is set to the set value RED-1 under the first signal condition. Then, in step S1203, the radio signal under the first signal condition is received.

Next, in step S1204, the control output CN4 for switching the AGC gain control amount is output from the signal processor section 407 to the gain control circuit 406 according to the signal format when the signal condition switches from the first signal condition to the second signal condition. Then, in step S1205, according to the control signal CN4, the AGC gain control amount is converted into the set value RED_2 under the second signal condition, and then set to this value. Next, in step S1206, a radio signal under a second signal condition is received.

In the case where the radio receiver corresponds to a radio receiver performing a discontinuous receiving operation, in step S1206, the receiving operation is completed. If the receiving operation is performed again, the processing from steps S1202 to S1206 is repeated. On the contrary, in the case that the radio receiver corresponds to a radio receiver performing a continuous receiving operation, the process proceeds to step S1207, where the A control signal CN4 for switching the AGC gain control amount is output from the signal processor section 407 to the gain control circuit 406 . Then, the processing returns to step S1202. The receiving operation is continued by repeating the processing from steps S1202 to S1206.

As described above, according to the radio reception method of the fourth embodiment, when receiving a signal having a signal format that is simultaneously transmitted while changing transmission conditions such as transmission data speed into two types or more types, the control signal CN4 is output from the signal processor section 407 to the gain control circuit 406 at signal condition transition timing to change the setting of the gain control circuit 406 and thus change the gain control amount of the AGC circuit. Therefore, the optimum gain control of the gain control means can be achieved to suit the signal transmission conditions, with the result that the communication quality under mobile radio communication can be considerably improved.

In summary, the first, second, third and fourth embodiments have been described above. The first and third embodiments can be applied to a stepped gain control type AGC circuit and a continuous gain control type AGC circuit, when the signal level of the received signal exceeds a predetermined level after the electric field strength reaches the electric field strength level threshold for starting the AGC operation , the stepwise gain control type AGC circuit changes the gain by a predetermined value; the continuous gain control type AGC circuit changes the gain according to the signal level of the received signal after the electric field strength reaches the electric field strength level threshold for starting the AGC operation. The second and fourth embodiments can be applied only to the stepped gain control type AGC circuit. In addition, as a modification of the embodiment that can be applied to the stepped gain control type AGC circuit, the combined modification of the first and second embodiments and the third and fourth embodiments can be applied.

Combination variants of the embodiments.

In the first, second, third, and fourth embodiments described above, the description is made on the assumption that the receiving system is a heterodyne system. However, these embodiments may utilize other receiving systems as well. For example, a direct conversion system, etc. are implemented, and therefore, the receiving system should not be particularly limited.

As described above, according to the radio receiver, the radio receiving method, and the recording medium of the present invention, the electric field strength level threshold value for starting the AGC operation of the gain control device based on the measurement result of the error rate measuring device is determined by starting the AGC operation The electric field strength level threshold setting device (starting the electric field strength level threshold setting step of AGC operation) is set, when the electric field strength detected by the electric field strength detection device reaches the electric field strength level threshold starting AGC operation, the first control device ( The first control step) causes the gain control means to start a gain control operation. Therefore, since the threshold value of the electric field strength level at which the AGC starts the AGC operation is set based on the measurement result of the error rate of the received signal, the threshold value of the electric field strength level at which the AGC operation is optimally started can be set to suit the radio receiver where the radio receiver is located. The wave environment, that is, the reception environment in which the signal is received, and gain control of the gain control device can be obtained under an environment characterized by IM or an electric field change, for example, in an environment of strong electric field IM, or an environment in which the electric field changes strongly To optimize the signal quality of the received signal. As a result, the communication quality in mobile radio communication can be considerably improved.

Furthermore, according to the present invention, the gain control amount of the gain control means is set by the gain control amount setting means (gain control amount setting step) based on the measurement result of the error rate measuring means, and the second control means (second control step) makes The gain control means changes the gain according to the gain control amount. Therefore, since the AGC gain control amount is set based on the measurement result of the error rate of the received signal, the optimum AGC gain control amount can be set to suit the radio wave environment in which the radio receiver is located, i.e., the reception environment of the received signal, and The gain control of the gain control means may be obtained to optimize the signal quality of the received signal in environments characterized by IM characteristics or electric field variations, for example, in environments of strong electric field IM, or environments in which electric fields vary strongly. As a result, the communication quality in mobile radio communication can be considerably improved.

And, according to the present invention, when a signal having a signal format that is simultaneously transmitted while changing transmission conditions such as transmission data speed into two types or more types is received, the electric field strength level threshold to start the AGC operation Setting means (the electric field intensity level threshold value setting step of starting AGC operation) sets the electric field intensity level threshold value starting AGC operation according to the transmission condition of the signal, to start the gain control operation of the gain control means, and when the electric field detected by the electric field intensity detection means When the strength reaches the electric field strength level threshold for starting AGC operation, the first control means (first control step) causes the gain control means to start the gain control operation. Therefore, since the threshold value of the electric field strength level at which the AGC operation is started is set to be suitable for the transmission condition of the signal, the optimum gain control of the gain control means can be obtained to be suitable for the transmission condition of the signal. As a result, in mobile radio communication Communication quality can be considerably improved.

Furthermore, according to the present invention, when receiving a signal having a signal format transmitted while changing transmission conditions such as transmission data speed into two types or more, the gain control setting means (gain control amount setting Step) Setting the gain control amount of the gain control means according to the transmission condition of the signal, and changing the gain of the gain control means according to the gain control amount by the second control means (second control step). Therefore, since the gain control amount is set to be suitable for the transmission condition of the signal, the optimum gain control of the gain control means can be obtained to be suitable for the transmission condition of the signal, as a result, the communication quality in mobile radio communication can be considerably improved. improve.

Claims (3)

1. A radio receiver for receiving a signal having a signal format transmitted while changing a transmission condition into two types or more types, comprising: Gain control means for controlling the gain of the radio receiver; gain control amount setting means for setting the gain control amount of the gain control means according to the transmission condition of the received signal; and The control device is used to make the gain control device change the gain according to the gain control amount. 2. The radio receiver according to claim 1, wherein the gain control means is of a stepped gain control type which changes the gain by a predetermined value when the signal level of the received signal exceeds a predetermined level. 3. A radio receiving method for a radio receiver, wherein the radio receiver includes gain control means for controlling the gain of the radio receiver, and receiving has A signal of a simultaneously transmitted signal format of type, the method comprising the steps of: a gain control amount setting step of setting a gain control amount of the gain control means according to a transmission condition of the received signal; and A control step of causing the gain control device to change the gain according to the gain control amount.

Images